With the development of Chirped-pulse Amplification (CPA) and Optical Parametric Chirped-Pulse Amplification (OPCPA) techniques, ultrafast and ultraintense laser pulses can generate extreme physical conditions at lab such as ultrafast time, ultraintense electric field, ultrahigh magnetic field, ultrahigh temperature and ultrahigh pressure, which makes ultrafast and ultraintense laser pulses one of the most powerful tools to extend human's knowledge of the physical world. In the development of ultrafast and ultraintense lasers, femtosecond four-wave mixing process which is a third-order process and does not need anisotropic nonlinear crystals plays an important role in many aspects. Here, the development and application of femtosecond four-wave mixing processes on ultrafast and ultraintense laser pulses are discussed. Femtosecond pulses from Ultraviolet (UV) to Near-infrared (NIR) can be generated based on the Cascaded Four Wave Mixing(CFWM), which is of great significance in ultrafast spectroscopy, ultrafast microscopy and high temporal contrast seed pulse generation. By manipulating the spectral dispersion property, the polarization property, the spatial phase, or the crossing angle of the input beams, the CFWM signal with interesting properties can be generated. In this review article, the generation of spatially separated multicolored femtosecond sidebands from UV to NIR, the generation of high-performance seed pulses with high temporal contrast based on the CFWM or self diffraction process, and the generation of multicolor concentric annular ultrafast vector/vortex beams are demonstrated. Furthermore, based on the four wave mixing process, the generation of broadband ultrashort light pulses from narrowband seeds in transparent media can be realized. Broadband light pulses with a spectral width of hundreds of nanometers can be generated with narrowband light pulse seeds. Cross-correlator is the main method for high-dynamic single-shot temporal contrast measurement for the ultrafast and ultraintense laser pulses. Benefiting from excellent temporal domain filtering and high-energy signal generation of four-wave mixing, a single-shot Fourth-order Autocorrelation (FOAC) which consists of a four wave mixing process and a sum-frequency mixing process is developed. The signal of the self-diffraction process, or XPW process is used as the sampling pulse of the FOAC. And the stable devices with high dynamic range, wide time window, high temporal resolution, excellent measurement fidelity are combined in the proposed FOAC device, which can be helpful to investigate the temporal contrast property of high power laser pulses and realize better laser-matter interaction research. The Self-referenced Spectral Interferometry (SRSI) method with high time resolution of as high as 20 fs can also be used for the single shot temporal contrast measurement. However, the dynamic range is limited by the signal-to-noise ratio of the detector. To further improve the dynamic range, novel temporal contrast reduction techniques are proposed. The proof-of-principle experiments applying single stage of pulse stretching, anti-saturated absorption, or optical Kerr effect successfully reduce the temporal contrast by approximately one order of magnitude. The dynamic range characterization capability of the SRSI method is improved by about one order of magnitude to 10⁹.To characterize the temporal profile of femtosecond pulses, the SRSI method is also an analytical, sensitive, accurate, and fast method. We have developed the Self-diffraction Effect-based SRSI (SD-SRSI) and Transient-grating (TG) Effect-based SRSI (TG-SRSI) for temporal profile characterization. The characterization of sub-10 fs pulse with a center wavelength of 1.8 μm is demonstrated. On the basis of the TG effect, the SRSI and the Frequency-resolved Optical Gating (FROG) are combined together to further extend the measurement ability. Weak sub-nanojoule pulses from an oscillator are successfully characterized using a TG-SRSI device, and the optical setup of which is smaller than the palm of a hand. The compactness of the SISR device makes it convenient to use in many applications, including monitoring the pulse profile of laser systems as a sensor. In the future, the femtosecond four-wave mixing processes can be extended to the EUV and THz spectral ranges, which will extend the application range of ultrafast and ultraintense laser technology.