The invention relates to an anti-off structure of a subway vehicle obstacle detection device. An obstacle detection device comprises a connecting box and two spring plates arranged in the connecting box; a through hole is formed in the back of the connecting box; a thread sleeve is arranged in the through hole; a bolt fixes the obstacle detection device to a framework connecting piece after penetrating through the two spring plates and the thread sleeve in sequence; a rubber pad is arranged in a gap between the back of the connecting box and the framework connecting piece; a connecting cross rod penetrating through the interiors of the spring plates is also fixed in the connecting box; and the two ends of the connecting cross rod are fixed on the framework connecting piece through anti-offropes. According to the anti-off structure of the subway vehicle obstacle detection device, a stress effect is not generated during the normal mounting of equipment; and after a detection device mounting point is invalid, the anti-off structure generates an effect to prevent safety accidents. The anti-off structure of the subway vehicle obstacle detection device has the advantages of high reliability, simple operation, convenient mounting and low cost. Moreover, the hanging distance is short, the swinging amplitude is small when the anti-off structure is valid, the operation limitation is met, and no secondary damage can be caused.