The invention discloses a metal surface laser bar code depth measure method comprising the following steps: 1, making a sample clamp including two clamp plates, wherein the clamp plate is provided with two thread holes, bolts used for connecting two clamp plates are arranged in the thread holes, and nuts are arranged on the bolts; 2, clamping a sample: preparing a tested sample with a laser bar code, linear cutting the tested sample in a vertical direction of the laser bar code so as to form a tested surface, using the sample clamp to clamp the tested sample, and polishing and grinding the tested surface; 3, using a stereoscopic microscope to tag a zone, close to the laser bar code, of the tested surface, using a metalloscope to find the tagged position, carrying out micrographing on the cross section depth of the laser bar code, and finally using quantification metallographic measure software to measure the laser bar code depth. The method is simple in operations, and can accurately measure the depth of the laser bar code on the metal surface.