Research on the tectonic and thermal evolution of coal measures' source rocks is of great significance for revealing the generation mechanism of coal-measures gas. To reveal the process of tectonic-thermal evolution， the stage of hydrocarbon generation and expulsion， and the genetic types of the coal-measure gas， the thermal and hydrocarbon generation evolution histories of the source rocks in the Mesozoic coal measures in the Huangling mining area were studied in this paper， based on the data of lithology， buried depth， porosity， maximum vitrinite reflectance， carbon and hydrogen isotopic compositions of methane and biogas yield and with the use of the methods of Petromod 1D simulation， back-stripping inversion， and EASY% R_O. The results show that the Mesozoic coal measures experience thrice-quartic "subsidence-uplift" stages in the Huangling mining area since the beginning sedimentation at the Late Triassic. The hydrocarbon generation process can be divided into three phases. The first stage is the primary biogas generation period during the Late Triassic to the early middle Jurassic. The maximum vitrinite reflectance evolved to 0.3%. In the second period of thermogenic gas generation during the early Middle Jurassic to late Early Cretaceous， the burial depth and thermal temperature of the coal measures continuously increased to the highest level at the end of the Early Cretaceous. The maximum vitrinite reflectance evolved to 0.67%~ 0.74%. In the third period of secondary biogas generation during Early Eocene so far， the coal measures' burial depth is uplifted to 2 077~2 148 m， and the thermal temperature is decreased to less than 75 ℃. The data of the carbon and hydrogen isotopic composition of methane and the accumulatively generated methane amount of 10.5~16.1 μmol/g during the experiment of microbial degradation No. 2 and No. 3 coal provide evidence for the occurrence of secondary biogenic gas in the Huangling mining area.