A big viewing field scanning thermal imaging system based on a staring imaging mode relates to a big viewing thermal imaging system and solves the problem that the viewing filed and the space resolution ratio in the existing thermal imaging system are contradictory. The big viewing field scanning thermal imaging system comprises an aperture diaphragm, a first lens group, a second lens group, a cold diaphragm and a two-dimensional movable rack; a big viewing field imaging system formed by the aperture diaphragm and the first lens group adopts a telecentric beam path form in image space; a small viewing field staring imaging system formed by the second lens group and the cold diaphragm is fixed on the two-dimensional moving rack, the movable direction of which is vertical to an optical axis; the input end of the small viewing field staring imaging system is connected with the output end of the small viewing field staring imaging system; and the cold diaphragm is positioned at the output end of the second lens group. The imaging system utilizes the two-dimensional moving rack to drive the small viewing field staring imaging system to move, thus realizing the scanned imagery on primary image surface. The imaging system has the advantages that the system combines the small viewing field stared imaging and the big viewing field scanned imagery, and both can be used for infrared target detection and thermal imaging scouting.