The invention relates to a laser marking device. The laser marking device includes a support platform, a rotation platform, a clamp assembly, a switch assembly and a laser marking head; the rotation platform is rotationally arranged on the support platform; the clamp assembly includes a push drive part, a rack, a gear, a mounting block, a mounting shaft and a clamp drive part, the push drive partis mounted on the rotation platform, the rack is connected to the push drive part, the gear meshes with the rack, the mounting block is fixed to the gear, the mounting shaft is rotationally arranged on the mounting block in a penetrating mode, a clamp end is formed at one end of the mounting shaft, and an adjusting groove is formed in the other end of the mounting shaft. The laser marking device is relatively small in size and relatively simple in structure.