Unconventional oil and gas geology theory is a theoretical leap from conventional oil and gas to unconventional oil and gas in the world petroleum industry. By the close integration with China’s special geological background and oil and gas industry conditions and through a decade of unremitting efforts, by constructing disciplines such as fine- grained sedimentology, unconventional oil and gas reservoir geology, unconventional hydrocarbon accumulation geology, unconventional oil and gas development geology, and the development strategy of the “coexistence basins” of conventionalunconventional oil and gas, the framework of the unconventional oil and gas geology theoretical system has been basically formed. The unconventional oil and gas geology theory is the theoretical basis for the development of typical unconventional oil and gas industries such as shale oil and gas, tight oil and gas. It has promoted the development of petroleum geology, the development of industry standards, the construction of national laboratories and the cultivation of professional talents. Further, it has facilitated the industrial exploration and development of unconventional oil and gas resources such as tight oil and gas, shale oil and gas in China. Unconventional oil and gas geology still has room for development in the future comprehensive utilization of oil and gas resources, scientific prediction of energy structure, and innovative solutions to complex problems.