Blood pump

The invention relates to a blood pump. The blood pump comprises a pump body, a rotating shaft assembly and a transmission assembly. Wherein the pump body comprises a pump shell and an impeller, the pump shell is provided with a blood flow channel and a driving cavity, and the impeller is rotatably arranged in the blood flow channel; the rotating shaft assembly comprises a flexible shaft and a hard shaft; the hard shaft is provided with a first end and a second end which are opposite, the first end is fixedly connected with the impeller, and the second end is located in the driving cavity. The flexible shaft is provided with a driving end used for being connected with an in-vitro motor and a transmission end far away from the driving end, and the transmission end is located in the driving cavity and opposite to the second end of the hard shaft. The transmission assembly is arranged in the driving cavity and comprises a first magnetic group and a second magnetic group; the first magnetic group is fixedly connec