A key clamp for key processing machines and key processing machine comprising a base, a first clamp and a second clamp, have the same structure and are arranged in parallel on the base, and they both have a fixed connection with the base. The first clamp comprises at least three clamping jaw and a transmission device, three clamping jaws arranged in one row, the first clamping jaw and the third clamping jaw are both fixed in relation to the base. The second clamping jaw is flexibly installed on the base. The transmission device penetrates the first clamping jaw, the second clamping jaw and the third clamping jaw, and are connected to the second clamping jaw. The key clamp can clamp house keys and automotive keys with a multitude of structures. It has the advantages of strong versatility, simple structure, easy use and reliable clamping.