The invention relates to an aspiration device, in particular to a thrombus aspiration device, and belongs to the technical field of medical instrument structures. The thrombus aspiration device comprises a metal sheath, a rotary cutter and an expander. The metal sheath comprises a metal spiral pipe, a side pipe is arranged at one end of the metal spiral pipe, and one end of the side pipe is movably connected with a first backflow preventing cap. The rotary cutter comprises a crank, a spiral flow guide groove is formed in the end, away from the handle, of the rotary cutter, a second backflow preventing cap is arranged at the end, close to the handle, of the rotary cutter, and a blade is arranged between the second backflow preventing cap and the spiral flow guide groove. The thrombus aspiration device can replace an original long metal sheath, the expander is withdrawn, the rotary cutter is fed in, the thrombus aspiration device is formed, the side pipe generates negative pressure through pumpback of an injector, thrombus is made to enter the metal sheath, the rotary cutter is rotated, the thrombus is conveyed to move into a lumen under the combined action of the rear driving force of the flow guide groove and the negative pressure, the middle blade cuts the thrombus into small blocks, the thrombus is sucked out of the side pipe, the situation that large thrombus blocks block the pipe cavity, and consequently the aspiration process is interrupted is avoided, operation efficiency is improved, and operative complications are reduced.