Thrombus filter comprising a sleeve (1), a thrombus intercepting network (2) with an intercepting joint, a first thrust piece (4) to drive the thrombus intercepting network (2) into and out of the cover (1) and a control handle to control the first push piece (4), the filter further comprising an overfill prevention umbrella (3), in which the direction of an opening of the overfill prevention umbrella (3 ) is identical to that of the intercepting joint, and a second push piece (5), which is located in the cover (1) to push and pull the overfill prevention umbrella (3)； characterized in that the overfill prevention umbrella (3) is arranged in the form of a sleeve on the outside of the thrombus interception network (2): where the overfill prevention umbrella (3) comprises an umbrella support (31) and an umbrella surface (32), the umbrella holder (31) having one end connected to the second push piece (5) and its other end being connected to the umbrella surface (32), and one open end being the umbrella surface (32) in a contracted memory shape； wherein, when the thrombus intercepting network (2) is released, the opening of the overfill prevention umbrella (3) is pushed open by the intercepting joint of the thrombus intercepting network (2)； and wherein, when the thrombus intercepting network (2) is returned, the umbrella surface (32) of the overfill prevention umbrella (3) covers the intercepting joint of the thrombus intercepting network (2) and the open end of the surface (32) contracts to prevent thrombus leakage.Filtro para trombos que comprende una funda (1), una red de interceptación de trombo (2) con un empalme de interceptación, una primera pieza de empuje (4) para conducir la red de interceptación de trombo (2) dentro y fuera de la funda (1) y una empuñadura de mando para controlar la primera pieza de empuje (4), comprendiendo además el filtro un paraguas de prevención de sobrellenado (3), en el que la dirección de una apertura del paraguas de prevención de so
