A full-automatic rock specimen image acquisition device and method, the device includes a central controller and a lighting system, a rock mass attitude control system, a dust system and an image acquisition system connected to the central controller respectively; the lighting system includes a lighting chamber and light sources with adjustable light intensities, and the light sources with adjustable light intensities are uniformly arranged in the lighting chamber; the rock mass attitude control system includes a rotating stage disposed in the lighting chamber for carrying the rock, a rock holder disposed on the stage, and a rotating gripper disposed above the stage for turning over the rock; and the dust system is connected to the lighting chamber, and can diffuse the dust into the lighting chamber through an air compressor and control the dust concentration in the lighting chamber through an electrostatic precipitator.