Abstract: Creep damage of the platinum reforming reactor fabricated with 10CrMo910 steel,which had serviced for about 150 000 h,had been comprehensively investigated by observing the microstructure and testing the mechanical properties at room temperature and elevated temperatures.The remanent life was caculated.The results show that the chemical composition of the reforming reactor was normal,but carbides had been spheroidized,phase transformation occurred on the carbides and the obviously temper brittleness appeared after long-term service,the brittle ductile transition temperature increased from -44.6℃ to 13.7℃.Combining the high temperature stress rupture test and Larson-Miller extrapolation methods,remanent life of the reactor had been prolonged,which was 201 671 h.