To measure the lamp installation clearance, this paper proposes a method for measuring the installation gap of the headlights based on the combination of laser scanning technology and industrial robot technology. The method simulates a vehicle body with a gage and establishes a measurement system for a lamp installation gap. First, the laser scan data is preprocessed to remove the invalid data points of the overrange, and then the bilateral filter is used to smooth the data denoising. Through the selection of the height difference threshold in the determination algorithm of the boundary point of the vehicle lamp and the inspection tool, the boundary point between the vehicle lamp and the inspection tool is found, and the gap size is determined by the lamp installation clearance calculation model. The experimental results show that the measurement method has high accuracy, high efficiency, and repeatability also meets the requirements.