The invention relates to the technical field of cutting device accessory devices, in particular to an assembly type building wall body cutting device. According to the assembly type building wall bodycutting device, the difficulty of cutting an assembly type wall body according to a specified track can be reduced by limiting the cutting track of a cutting piece; moreover, the cutting difficulty of the assembly type wall body can be reduced by flexibly adjusting the cutting track; and meanwhile, by additionally arranging a control device, an operator can save more effort when using the cuttingdevice, and the difficulty of controlling the cutting depth of the cutting piece of the cutting device can be reduced. The cutting device comprises a motor, the cutting piece, a fixing plate, a connecting sliding block, an adjusting screw, a control panel, a fixing ring, two fixing rods, two rotating rings, a fastening screw, a control ring and a limiting screw, the left end and the right end ofthe fixing plate are provided with two moving grooves correspondingly, an annular groove is formed in the side wall of the inner circumference of each rotating ring, the cutting device further comprises a control threaded rod, a fixed bearing, two positioning rods and a rotating disc, and a rotating cavity is formed inside the right side of the control panel.