A filter (10), comprising a heart-proximal end (1), a heart-distal end (2) and a main filter body connected between the heart-proximal end (1) and the heart-distal end (2). The main filter body comprises a first filter unit (3) and a second filter unit (4), both being conical mesh structures, as well as multiple intermediate connection posts (5) connecting the first filter unit and the second filter unit. The intermediate connection posts (5) have provided thereon support posts (6). A support post (6) comprises a transition segment (61) extending from an intermediate connection post (5) to a blood vessel wall, and a support segment bent and extending from the transition segment (61), and at least partially abutting the blood vessel wall. The support segment comprises a main body (62) bent and extending from the end of the transition segment (61) and a flexible segment (63) bent and extending from the main body (62). A diameter of at least a portion of the flexible section (63) along a length thereof is smaller than a diameter of the main body (62), thereby increasing flexibility of the support section and preventing the support section from puncturing the blood vessel wall.
