The application discloses a high parallelism installation method of a large target surface sensor and a camera. The installation method includes: step 1, fixing the front shell and the lens flange on the processing platform respectively, Parallelism processing, wherein, the processing plane of the front shell includes the third plane and the fourth plane, and the processing plane of the lens flange includes the first plane and the second plane; step 2, according to the first positioning hole and the first positioning post, the The processed front shell and the processed lens flange are assembled, which is recorded as an assembly; step 3, based on the first plane of the lens flange, fix the assembly on the processing platform; step 4, the front shell The sensor mounting surface is processed for parallelism, and the processed sensor mounting surface is parallel to the first plane of the lens flange. Through the technical solution in this application, it is beneficial to reduce the cumulative error of the parallelism between the sensor assembly surface and the lens, thereby improving the imaging effect of the image sensor.