Single-photon counting imaging technology has demonstrated potential for applications in faint target detection, laser remote sensing, and automatic driving. Therefore, in order to explore it for obtaining more dimensional target information, a target attitude acquisition method is proposed and verified. The single-photon counting three dimensional (3D) images (depth images) of the target in different attitudes are built into a database as a priori information. By calculating the correlation coefficient between the database image and the actual single-photon counting image (unknown attitude) of the target, the most relevant attitude in the database is selected as the actual attitude. A single-photon array detector is then used to establish the experimental system, and the target is illuminated by a diverging laser. The target depth images with attitudes between -60° to 40° in the database are constructed with 20° at increments. Combining database depth images and target depth images with attitudes of -45° and 25°, the proposed method is used to estimate the target attitude as well as verify its accuracy. Under these two postures, depth images with photon counts of 10, 50, and 100 are made, respectively,to explore the relationship between the similarity and photon count between the actual posture of the target and the corresponding posture in the database. The multi-axis rotation of the target was conducted at 15° and 20° to explore the proposed method's feasibility when the multi-axis change of target attitude occurs. To explore the influence of background noise on estimation success rate, the background noise was changed and 3D imaging was conducted for the target under the condition that the signal photon counts to background photon counts ratio (SBR) is 8.13, 4.83, 3.21, and 0.72, respectively. Using wood man as the target, the database is established with 30° as the unit, and the wood man at -20° and 20° is imaged while the proposed method's feasibility for complex target attitude estimation is verified. Experimental results show that the proposed method can successfully estimate the actual attitude of the target. Meanwhile, correlation between the actual attitude of the target and the corresponding attitude in the database is positive with the photon count. High SBR is also conducive to accurate estimation of the target attitude.