Precambrian geology is one of the major research fields of earth sciences. There are abundant mineral resources in the Precambrian rock formations, on which the survival and development of mankind depend. And the Precambrian was a main period of the growth of the continental crust. Therefore the origin, formation and evolution of the continental crust and their model are some of the most important problems to which earth scientists pay close attention. The outcrops of the Precambrian middle-to high-grade metamorphic rocks are regarded as "windows" for studying the deep levels of the crust, which starts a new means and provides new information for the lithospheric research. The study of organic origin and its early evolution must be based on fossils in Precambrian strata. Through an overview of the development history of earth sciences, the author holds that Precambrian geology is a significant research field that can not be replaced by other subdisciplines of earth sciences.