Petroleum sulfonate is obtained through sulfonate reaction using extract oil from refining VGO.no.5 in the No.1 refinery of Fushun as raw materials and oleum as sulfonation agent in this paper. And the effect of reaction conditions such as acid/oil ratio, temperature and reaction time on product yield is studied. The yield of petroleum sulfonate is 64.14% when acid/oil ratio is 0.12∶1, temperature is 60 ℃and reaction time is 45 min. After petroleum sulfonic acid is reacted with 10% sodium hydroxide, petroleum sulfonate is obtained by extraction with ethanol and its active substance content is 42.1%, which can be used as surface active reagent.