The invention discloses a laser scanning device and method applied to three-dimensional scene measurement. The device includes a light source, a laser phase modulator, an optical grating, a reflector, a lens, a distance measurement light receiving part and an imaging light receiving part; the laser phase modulator and the optical grating form a laser deflection part for laser modulation, a traditional rotating lens deflection method is replaced, and high-frequency laser scanning can be achieved. The combination of the laser phase modulator and the optical grating replaces a rotating lens, deflection scanning is conducted on light beams, the scanning frequency is only limited by the modulation frequency of the phase modulator and can reach the level of GHz, a deflection member has no mechanical movement, and therefore starting delay caused by inertia of the member is avoided and influence of motion friction on the service life of the device is avoided.