The invention belongs to the technical field of dust collection mechanisms, and in particular to a dust collection mechanism for a sweeping robot. In order to solve problems of dust collection mechanisms which are relatively simple in design structure, single in function and relatively poor in dust collection effect and dust removal effect, according to the scheme, the dust collection mechanism comprises a shell, wherein driving wheels fixed to four corners of the outer wall of the bottom of the shell via screws; a dust collection box is fixed to the interior of the shell via screws, and a fanis fixed to the outer wall of the top of the dust collection box via screws; an exhaust head sleeves the input end of the fan; a baffle plate, which is horizontally arranged, is welded on the inner wall of the dust collection box, and two mounting holes are formed in the outer wall of the bottom of the baffle plate; and a dust collection bag is connected to the inner walls of the two mounting holes via screw threads. The dust collection mechanism provided by the invention can achieve a good dust collection effect, so that dust collection efficiency of the sweeping robot can be obviously improved, pollution of indoor air caused by dust leakage can be prevented and a good living environment can be created; therefore, people's body health is guaranteed, and service life of the device (the dust collection mechanism) is prolonged.