The invention discloses a gasless minimally invasive surgery auxiliary device. The device comprises a supporting tail end, a tool box and a tool rod, wherein a tool box transmission device is installed in the tool box, the supporting tail end comprises a rear supporting base and a front supporting base, a plurality of grooves are arranged on the rear supporting base and the front supporting base along peripheral directions respectively, a rear pin roll is connected with each of the grooves of the rear supporting base, a front pin roll is connected with each of the grooves of the front supporting base, each of groups of front pin rolls and rear pin rolls, which are arranged corresponding, are connected through connecting parts, the rear supporting base is fixed at the front end of the tool rod, the front end of the supporting shaft is connected with the front supporting base fixedly through a supporting head, the rear end of the supporting shaft penetrates through a central hole of the tool rod and is connected with the tool box transmission device, under the driving of the tool box transmission device, expansion and rotation motions are conducted, and the front supporting base can perform expansion motion relative to the rear supporting base under the driving of the supporting shaft. According to the device, the compression effect for other parts such as the chest, caused by the fact that the abdominal cavity is aerated, can be reduced.