Abstract: In this paper, the sintering mechanism of GF3 high-speed steel powders has been investigated by means of a cylinderically converging explosive method with a ring-shaped flyer.It has been shown that shock waves produce high temperature and high pressure in a few microseconds, which leads to that melting occurs at the interface of the metallic powders and caructure causes inter-particle welding resultion in microcrystaline structure and sintering of powder particles in the rapid solidifying process followed.