In order to reflect the distribution of the performance of each region on the geometric scale of the device, a laser beam with a wavelength of 852 nm and an adjustable focusing area was used to act on the surface of the P-N junction microregion of the CdTe thin-film solar cell to generate a localized induced photocurrent. By setting the step-by-step method of the sample stage, the micro-region spectral response distribution map of the measured device within the geometric area range was obtained, and a more intuitive device current distribution uniformity and P-N junction characteristics were obtained. The results show that the relationship between the deposition and post-processing parameters and material properties that are closely related to the CdS/CdTe heterojunction fabrication technology can be simplified and cost-effectively established by using this test method, and then the heterojunction interface distribution uniformity and solar cells can be obtained. The corresponding relationship of the uniformity of I-V characteristic parameters provides experimental test basis for improving the performance of solar cells.