The utility model discloses an arrestment mechanism for car belongs to the stopper production field. Actuate and open the device, including the brake shoe, the external friction piece, actuate an opening mechanism and braking bottom plate, two brake shoes set up relatively, and the lower extreme of two brake shoes is articulated with the braking bottom plate through the supporting pin axle respectively, install return spring between the middle part of two brake shoes, the upper end of two brake shoes all with actuate an opening mechanism transmission and be connected, the outer disc of axial of brake shoe is vice with the friction of external friction piece component, its characteristics are friction surfaces of external friction piece, the cambered surface of protruding formula or two inclined planes that the symmetry set up in its axial tangent plane is, the friction surface of brake shoe is vice with a pair of friction of the friction surface of external friction piece constitution, and its axial tangent plane is the cambered surface of indent formula or two inclined planes that the symmetry set up. Compared with the prior art, the utility model discloses an arrestment mechanism for car has characteristics such as heat dispersion is good, the braking is steady, braking distance is short.