Abstract: Security and protection surveillance lens is becoming more and more important in protecting personal and property safety, among which the pinhole lens is widely used because of its special structure. A pinhole lens was designed by using ZEMAX software for special occasions such as police forensics, reconnaissance, anti-terrorism as well as high temperature furnace and industrial inspection, etc. Aiming at the asymmetric optical system with the diaphragm in front of, the geometrical aberrations such as astigmatism, field curvature and distortion were controlled to optimize the design. The F number of the designed lens is 2 and the focal length is 6 mm. The lens matches 1/4 inch CCD, and the working spectrum is the visible light band, with the full field MTF≥0.48 at space frequency 100 lp/mm and the distortion ≤±3%. The designed structure is simple, which adopts the standard spherical design. The optical total length is less than 22 mm, which means better processing technology and low production cost. The tolerance analysis of the lens was analyzed, and the results show that the optical system has reasonable tolerances, good overall performance, and is feasible for mass production.