Abstract: The causes of thermal evolution anomalies in the Sichuan Basin, and the distribution of thermal fields and their main controlling factors during different geohistory periods were analyzed. The R_o-H thermal evolution profiles of typical wells and outcrops in various tectonic units in the Sichuan Basin were established to discuss the causes of vertical thermal evolution anomalies. The thermal field distributions in the Sichuan Basin from the Late Paleozoic to the Middle Triassic, the Late Triassic to the Jurassic, and at present, respectively, were obtained by a R_o gradient method, and a thermal history analysis was carried out. Some conclusions were made as follows. (1) Hydrogen generation from source rocks produced overpressure, leading to the differential inhibition of R_o and hydrocarbon cracking, which was the main cause of the "negative" anomaly of longitudinal organic matter thermal evolution in the Sichuan Basin. (2) The tectonic movements and basin properties in different periods controlled the vertical thermal evolution in the basin. At the end of middle Permian, regional extension changed the former unified low-heat field, resulting in increasing heat flow value in the fault depression, with an average geothermal gradient above 3.5℃/hm. From the Late Yanshanian to the Early Himalayan periods, the east part of the basin began to uplift, and the basin gradually shrank to the west. The peripheral thrusting action tended to decrease, and the high thermal field began to cool. The rapid uplifting and cooling effects at the end of Himalayan period formed the current low-heat field, with a geothermal gradient less than 2.5℃/hm.