Three-dimensional (3D) imaging technology based on single-photon avalanche diode (SPAD) array detectors has important industrial and scientific applications. However, existing SPAD array devices are limited by low spatial resolution due to small array size and low pixel-filling factor. Therefore, a coaxial scanning 3D imaging experiment system is built using a SPAD array (32 pixel×32 pixel) and a diffractive optical element (DOE). Using the DOE to shape an outgoing laser into a laser lattice and match it with the receiving field of view can improve laser energy utilization efficiency and achieve high-resolution 3D imaging through coaxial scanning. A noise photon-filtering algorithm based on a sliding time window and an image reconstruction algorithm based on total variational regularization are used to process the echo photon data. Experimental results show that, a 64 pixel×64 pixel 3D image of a target at a distance of 10 m can be obtained with an average of 0.86 signal photons per pixel to achieve clear imaging, the average absolute error of imaging results is 0.016 m.