Abstract: The simulation test of source rock under different heating time,added water amount and sample grain size was carried out.The yield of oil and gas in the simulation test of source rock varied obviously with different heating time,added water amount and sample grain size.When extending heating time,the oil yield was obviously decreased,and the gas yield of hydrocarbon was greatly increased.When added water amount was changed from 0% to 20% and to 50%,the gas yield of hydrocarbon,the remained oil,the expulled oil,the total oil yield and the total hydrocarbon yield were all obviously increased.When added water amount was more than 50%,the total oil yield and the total hydrocarbon yield were obviously decreased,but the gas yield of hydrocarbon was increased.From 1-2.5mm to 5-10mm of grain size,the total gas yield and the gas yield of hydrocarbon were obviously increased,and the total oil yield and the total hydrocarbon yield were obviously decreased.The simulation test of source rock under different heating time,added water amount and sample grain size showed that the component of oil,the GC and GC-MS of saturated hydrocarbon,the δ¹³C of gas and oil,the pyrolysis of kerogen,the H/C and O/C atom ratio of kerogen and other geochemical parameters were affected.