According to the comprehensive research of source rock burial history, geothermal history, organic matter maturity history, hydrocarbon generation rate evolution and cumulative hydrocarbon generation amount in the Dongling slope belt of Changling fault depression, it is considered that the source rock of K1h1 had two massive hydrocarbon generation and expulsion effects, which happened at the sedimentary end of K1h and during the basin depression stage. The first hydrocarbon generation and expulsion stage resulted in many self-generated and self-stored lithologic and stratigraphic oil reservoirs of K1h, while the second hydrocarbon generation and expulsion stage resulted in many structural and structural-lithological oil and gas reservoirs of K1h and its overlying fault-depression formations.