A laser detection and ranging (LADAR) device, including: a laser adapted to generate a laser emission path; an optical path scanning unit adapted to deflect the laser emission path and scan a target object using the laser emission path; a reflected light receiving unit coaxial to the laser emission path and adapted to receive a reflected light from the target object via the optical path scanning unit, and output an electric signal corresponding to the reflected light; a signal processing unit adapted to, according to the electric signal, generate distance information between the LADAR device and the target object, and process a plurality of acquired distance information, to yield position information of the target object; and a housing, including a filter disposed on the optical path of the optical path scanning unit.