Abstract: Analyzed here in the paper is the difference between the heat treatment process for massive production of the small-sized 12Cr1MoVG seamless steel pipe and the test sample heat treatment process,based on which targeted improvement measures are proposed. Due to the limitation of the type of the roller hearth furnace,even for the small-sized 12Cr1MoVG seamless steel pipe with the wall thickness of 10 mm only,the heat treatment process still needs to strengthen cooling.The problem of relatively low tensile strength of the product is well solved by means of installing an on-line spray device and reserving a certain distance at the discharge roller table,adopting the normalization cooling mode of“pre cooling + fog cooling + air cooling”.