Disclosed is a blood clot filter comprising a sheath (1), a blood clot intercepting net (2) with an intercepting port, a first pushing piece (4) and a control handle. The blood clot filter is also provided with prevention umbrella (3), wherein the direction of the opening of the overfill prevention umbrella (3) is identical to that of the intercepting port. The overfill prevention umbrella (3) is provided outside the blood clot intercepting net (2). A second pushing piece (5) is located in the sheath (1) to push and pull the overfill prevention umbrella (3). The overfill prevention umbrella (3) comprises an umbrella surface (32) and an umbrella stand (31) connected between the second pushing piece (5) and the umbrella surface (32), and the open end of the umbrella surface (32) is a closed shape memory. When filtering blood clots in blood vessels, the overfill prevention umbrella (3) is opened by the blood clot intercepting net (2)； after completion of the filtration, the blood clot intercepting net (2) returns into the overfill prevention umbrella (3) and the umbrella surface (32) of the overfill prevention umbrella (3) will be drawn into the centre of the intercepting port, in order to fully cover the intercepting port, thus preventing overflow of patches； the sheath (1) is pushed forward to retract the blood clot intercepting net (2)； and the overfill prevention umbrella (3) is pulled into the sheath (1). The blood clot filter can effectively recover calcified patches in blood vessels through the blood clot intercepting net (2) and the overfill prevention umbrella (3) can effectively prevent overflow of blood clots when being retracted after capturing blood clots.La présente invention concerne un filtre pour caillot sanguin comprenant une gaine (1), un filet d'interception de caillot sanguin (2) avec un orifice d'interception, une première pièce poussoir (4) et une poignée de commande. Le filtre pour caillot sanguin est également doté d'un parapluie de prévention
