The starting point of the evolution of the universe traced back to the Big Bang cosmology. It has a series of strange properties, infinite material density, infinite pressure, infinite curved space-time and so on. Many scholars have proved that in the cosmology of general relativity, "singularity" is inevitable, and the homogeneous and isotropic universe begins to expand from "singularity". 1970, British theoretical physicist Hawking and others put forward the "singularity theorem", which proved that when general relativity is applied to the universe, "singularity" will inevitably appear, not only in the large-scale universe, but also in the final outcome of the gravitational collapse of stars. Other scholars believe that the inevitability of "singularity" in general relativity may be a manifestation of its limitations. Einstein said: "People can't assume that these equations are still valid for high field density and material density, nor can they draw the conclusion that' the beginning of expansion' necessarily means a mathematical singularity." There is a speculation that there may not be a "singularity" at the beginning of the evolution of the universe. For example, Steven Weinberg (1933-) said: "The universe has never really reached infinite density. The current expansion of the universe may have started at the end of the last contraction, when the density of the universe reached a very high level, but it was still limited. " The debate about "singularity" involves philosophical issues such as causality and separability of matter.