Due to the night-vision display function of infrared images and their ability to observe targets over long distances, they are often used in sniper sights for firearms. However, when an infrared sight is first installed on a firearm, it is necessary to calibrate the zero position such that the cross-division center of the infrared sight coincides with the target center of the firearm during sniping. A target can only be accurately hit during sniping if the infrared sight has undergone zero calibration. Performing automatic and efficient zero calibration is a problem in that every infrared sight differs when it is first used. This article investigates the current mainstream zero calibration methods, analyzes and compares them, and proposes an efficient automatic calibration method and process based on single-key triggering, which simplifies the calibration process and improves its efficiency. In engineering applications, it solves the problem of difficult and slow calibration of infrared sights during initial use and greatly improves the user experience.