The temperature measurement system of melt pool produced in the process of laser rapid forming (LRF) is established by using a two-color infrared thermometer. The two methods named as real time tracking measurement and fixed point measurement are employed respectively to obtain the melt pool temperature and the cooling rate (temperature gradient) of the melt pool tail. The influences of LRF process parameters on the melt pool temperature are studied. The results show that with the increase of laser power and powder feeding rate the melt pool temperature rises. And the results just reverse as laser scanning speed increasing. With the number of deposition layer and deposition pass increasing, the LRF process presents characteristic of thermal accumulation effect, which means the melt pool temperature gradually elevates. Meanwhile the cooling rate (temperature gradient) of the melt pool tail takes on reverse trend.