Abstract: The 1Cr5Mo seamless steel pipe is mainly used for the petroleum cracking facility. According to Chinese National Standard GB 9948—2006 Seamless Steel Pipes for Petroleum Cracking Service, annealing process is required for heat treatment of such steel. Based on the result from relevant serial heat treatment process research, it is identified that adequate tempered sorbite structure can be obtained for the 1Cr5Mo seamless steel pipe by means of first undergoing normalization, and then tempering at 780 ℃ and with a soaking time at least 60 min, which ensures the pipe to possess excellent comprehensive performances, and tensile strength and hardness both up to applicable specification. It is concluded that thanks to normalizing + tempering heat treatment process, all the after- annealing performance index as specified in applicable specification for the above mentioned pipe can be fully satisfied.