Huajin straight-run naphtha produced by Northern Huajin Chemical Industry Group Co Ltd,Norinco Group was simulated and evaluated at pyrolysis temperatures of 838,843,848 ℃ and mass ratios of water to naphtha of 0. 50,0. 55,0. 60,0. 65 with Daqing straight-run naphtha produced from Daqing crude oil as reference sample. The results showed that the appropriate pyrolysis condition for Huajin straight-run naphtha was mass ratio of water to naphtha 0. 6 and temperature 843 ℃,and under this condition,hydrogen mass fraction in pyrolysis oil was 5. 44%-8. 38%,indicating that Huajin straight-run naphtha could be used as raw material for ethylene pyrolysis.