Thermal simulation experiments before and after hydrogenation of organic rich mudstone in Huanglong area of Shaanxi Province in closed system show that hydrogenation has a significant impact on the generation of saturated hydrocarbons and aromatics in source rocks, and the action stages are in the ranges of 200 ℃ to 400 ℃ and 400 ℃ to 500 ℃. At relatively low temperature, hydrogenation can inhibit the formation of saturated hydrocarbons, especially low carbon number saturated hydrocarbons; at high temperature, hydrogenation can promote the formation of low carbon number saturated hydrocarbons. The study on the product characteristics of different temperature stages of source rock evolution under different conditions is helpful to better understand the evolution process of source rock and the change of source rock after the change of external conditions, providing ideas for oil and gas exploration and fine evaluation.