The proportion of internal foreign matter is the largest in the insulation fault of GIS (Gas Insulation Switchgear) equipment, and when the foreign objects inside the long-tube structure GIS equipment are detected, the traditional vacuum cleaner cleaning and manual wiping methods are difficult to play an effective role. Based on the intelligent inspection and cleaning robot platform of the GIS equipment, this paper designs the dual-light source light filling technology which relies on the combination of ultraviolet light source and visible light source in order to clean the foreign objects in the GIS pipeline more effectively, and studies the foreign matter recognition algorithm to process images taken by robot using dual light source compensation, which can be used as a completely new scheme to check and verify the foreign matter defects of GIS equipment and to clean up foreign matter. Under the two kinds of light sources, the images taken inside the pipeline are processed to make foreign matter recognition judgment, which provides guidance for the robot to clean foreign matter. In this paper, while realizing the visualization of the foreign matter inside the GIS cavity, the problem that the single light source of the intelligent inspection and cleaning robot inside the GIS equipment is difficult to find some foreign particles is solved. It also avoids the problem that the robot needs manual experience to discriminate the foreign object, and improves the efficiency of the foreign object inspection inside the GIS equipment.