Abstract: In laser simulation combat systems, the traditional photoelectric detection circuit is significantly affected by the environment, the system is unstable, and the detection efficiency is low. To solve this problem, a gain-adaptive photoelectric detection circuit based on a single-chip microcomputer was designed according to the principle of photoelectric signal detection. Based on a traditional photoelectric detection circuit, two symmetrically distributed transimpedance amplification feedback circuits were used to eliminate the bias of the photodetector and suppress the system noise of the preamplifier circuit. An automatic gain-control circuit was used to stabilize the output signal amplitude at different shooting distances. The multistage filtering method was used to remove the DC component of the signal and effectively suppress the background noise, providing preparation for further signal processing. Experimental verification and TINA-TI simulation analysis show that the photoelectric detection circuit achieves an adaptive gain change, and the output voltage amplitude is stable at approximately 2 V at different incident distances. Its performance is clearly better than that of a traditional fixed-gain circuit, significantly improving the detection ability of the photoelectric signal. The results verified the scientific nature and feasibility of the proposed photoelectric detection circuit design.