The present invention relates to an occluder (100), comprising a meshed occlusion body (1) provided with a cavity (103), and a proximal hub (2), as well as a locking member (10) and a stopping member (13) both of which are located in the cavity (103). The distal end of the locking member (10) is connected to the distal end of the occlusion body (1). The stopping member (13) is disposed at the proximal end of the locking member (10). The proximal occluder head (2) is provided with a locking hole (15) in communication with the cavity (103). The radial size of the stopping member (13) is slightly larger than the diameter of the locking hole (15). The radial size of the locking member (10) is smaller than the diameter of the locking hole (15), and at least one of the proximal occluder head (2) and the stopping member (13) is an elastic member. An occlusion device comprises the occluder (100), a hollow delivery mechanism (200) and a traction member (4). The distal end of the traction member (4) is detachably connected to the proximal end of the locking member (10) of the occluder (100) after extending through the distal end of the delivery mechanism (200). The occlusion device has a simple locking structure, and simplifies the manufacturing process and the locking operation.