Micro-nano needle structure with continuously gradient morphology has the capacity of generating asymmetric Laplace pressure, simulating mechanical environment in nano newton grade, adjusting the ion migration rate etc., therefore, it has been widely applied in many fields such as microdroplet manipulation, biosensors, and ion rectification. However, in the previous fabrication of micro-nano needle structures with Two-Photon Polymerization (TPP), the structures were mainly constructed through the layer-by-layer scanning of laser focus. The bottom diameter or the height of the needle structure was usually in the grade of several or hundreds of micrometers. Further, the processing accuracy of the needles was generally in the grade of 100 nm, which resulted in the discontinuous morphology of the needle structures. On the other hand, the bottom diameter and structure height of micro-nano needle structures based on laser ablation or laser-assisted processing could be several micrometers, and the tip diameter could be less than 100 nm, however, the morphology and distribution of the needle structures were highly random. Considering the problems of precision, morphology and controllability in the previous fabrication of micro-nano needle structures, this paper proposes a novel method utilizing single voxel of femtosecond laser two-photon system to creating micro-nano needle-shaped structure with continuously changing morphology. In this methodology, a one-dimensional inclination angle is brought in the platform to automatically and linearly adjust the laser voxel to axially sink into the substrate completely as the stage is horizontally scanning. Finally, a micro-nano needle structure with continuous gradient morphology is produced. It is well known that, the voxel size in two-photon processing is the joint action of laser power, exposure time, scanning speed, and photoresist properties etc., the voxel might have similar size with different processing parameter combinations. Therefore, in this methodology, the size of the voxel should be calibrated firstly, and then people can determine the incline angle and corresponding processing parameters for the fabrication of needle-shaped structures. In order to facilitate the analysis of the processing results, in this investigation the scanning speed and the composition of photoresist materials are constant, and the laser power at the entrance pupil or inclination angle is selected as the variable to prepare micro-nano needle structures with different sizes. The TTP system in the experiment is built up based on femtosecond laser with a center wavelength of 800 nm. The photoresist is prepared with DETC as the initiator and PETA as the monomer. A single-axis goniometer stage, which is mounted on high precision nano stage, is utilized to configure the inclination angle of the sample. In the calibration, the laser power at entrance pupil is tuned to 3, 4, 5, 6, and 7 mW to produce the voxels with 50 ms exposure time. The lateral width of the corresponding voxels are 294, 478, 542, 621, 668 nm respectively. Meanwhile, the axial width of these voxels are respectively 720, 1 151, 1 561, 1 841, 2 060 nm. The increasing rate of lateral and axial line width will decline with the increase of power. Then, in the micro-nano needle structure fabrication, the center of the laser focus is located on the surface of the substrate at the beginning of fabrication. The incline angle is set to 1° and the platform scanning speed is 10 μm/s for scanning. A series of micro-nano needle structures with controllable length and gradually changing morphology are fabricated with fore-mentioned laser configurations. The SEM images show that the micro-nano needle structures with length of 17.3, 29.8, 40.4, 49.7, 58.1 μm are successfully obtained based on this method, which are slightly shorter than the theoretical fabrication length. It is probably caused by the declined in the concentration of the radical. As the focus gradually sink into the substrate, the effective laser intensity for exciting free radicals will decrease and lower the concentration of free radicals. Therefore, the voxel size will be reduced and result in a shorter length of micro-nano needle structure. At the same time, when the laser power is 4 mW, the inclination angles are 1°, 1.5°, 2°, and 2.5°, and other parameters are constant, the experiment fabricated structure length is consistent with the theoretical calculation. On the other hand, the topographic change gradient is positively correlated with inclination angle. It is also found that, the lateral line width of the micro-nano needle-shaped structure changes gently at the beginning of the fabrication, and changes quicker near as approaching to the end. This variation trend is determined by the structural characteristics of the single voxel, however, it does not affect the change continuity of the overall structure. The morphology change of the micro-nano needle in lateral direction is continuous in SEM observation. Further, it is seen from the AFM scanning results that benefiting from the processing principle of this fabrication methodology, the micro-nano needle structure exhibits a high-linearly gradient in height. The gradient fluctuation of the nano tips is in the order of several nanometers, and the minimum height of the nano tips could reach 5 nm. By using AFM calibration, the morphology of the nano tips are exhibited. The lateral line width gradient of the tip structure is smooth, and there are no step-like jump points. The minimum line width of the nano tips reaches 195 nm. It is noticed that, the nano tip structure changes faster in axial direction than lateral direction due to the shape feature of the voxel. In conclusion, the methodology that proposed in this work is effective and convenient for fabricating the micro-nano needle structures with high accuracy. The morphology of the experimentally fabricated needle structures are continuously gradated, and the precision of the fabrication achieved at the nanometer level. In addition, the experimental results are in high consistent with the theoretical predictions. It is worthy to mention that, the size of the TPP processing voxel can be further optimized by adjusting factors such as laser power, exposure time, photoresist, etc., which could produce finer and sharper nano tip structures. Such structures have potential applications in functional surfaces, micro-nano fluidics, and biosensing and other research fields.