When the laser diodes working, the losses of various non-radiating recombination and free carrier absorption are inevitable, so portion of the electrical power is converted into heat dissipation, which caused direct impact on the efficiency and lifetime of the laser. So the heat treatment has been a focus of attention. The micro channel heat sink is used to solve the problem of heat dispersing when the high power semiconductor laser array working, the structure parameters of the micro channel heat sink is optimized by using the ANSYS simulation software, and the thermal resistance of the high power semiconductor laser array is tested.