Thrombectomy device with controllable contraction and expansion of thrombectomy net

The thrombectomy device comprises the thrombectomy net, a pushing tube and a thrombectomy tube, the thrombectomy tube is provided with a tube cavity for containing the thrombectomy net and the pushing tube, the thrombectomy net has a radial shrinkage state and a radial expansion state, the near end of the thrombectomy net is fixedly connected with the far end of the pushing tube, and the far end of the pushing tube is fixedly connected with the near end of the thrombectomy net. The thrombus extraction device further comprises an action tube provided with a first action block and a second action block, the first action block and the second action block are both fixed to the action tube and arranged at intervals, and the far end of the thrombus extraction net is arranged on the action tube in a sleeving mode and can slide within the interval range defined by the first action block and the second action block. When the acting pipe moves in the preset direction and generates relative displacement with the pushing