The utility model provides a reflection apparatus for monitoring deep foundation pit wall displacement, comprising a mount and a conical surface reflector arranged on the mount; the mount is provided with a connection bolt; a bottom center of the conical surface reflector is provided with a screw hole; the conical surface reflector is in connection with the mount through the connection bolt. The beneficial effects are that directions of deep foundation pit wall displacement change can be effectively converted, and displacement variable quantity can be converted into parameters which can be identified by a monitoring device, which not only can automatically monitor displacement change of deep foundation pit walls and reduce manpower and material resources, but also can realize real time monitoring in order to timely discover potential safety hazard.