The invention discloses a depth-controllable rock sample drilling device and a utilization method. The problem about accurately drilling rock samples of different shapes is solved. The drilling devicecomprises a vertical rack, a drilling mechanism, an I-shaped slide mechanism, a caliper mechanism and a displacement mechanism, wherein pushing rods are arranged on a base of the vertical rack; the samples are fixed through the pushing rods; the pushing rods are provided with scales, so that the samples are accurately moved; clamping plates are arranged in front of the pushing rods; the clampingplates are changed to adapt to the samples of different shapes; and a through hole is formed in the center of the base of the vertical rack. According to the depth-controllable rock sample drilling device, holes of the processed samples are protected; stress springs are arranged in the slide mechanism, drilling force is controlled, and the drill sticking problem is avoided; and the outer surfacesof slides and the caliper mechanism are provided with scales, so that the drilling position and drilling depth are accurately controlled. The invention further discloses an operation method for drilling the rock samples of different shapes at different depths.