Adopting low-carbon power technologies is a crucial step in the power sector's sustainable growth. Macro data statistics that are transformed based on primary energy consumption make up the majority of the carbon emissions statistics used in the current research. The applicability of such technologies is constrained, and they do not reveal the features of carbon emissions from the power system. The three widely used methods of carbon emission detection are listed by the review method in this paper. Additionally, a novel concept of combining carbon emission analysis and power system power flow calculation is discussed, the concept of power system carbon emission flow is proposed, the significance of power system carbon emission research is highlighted by combining specific data, and finally the application field and research direction of power system carbon emission are discussed. The carbon emission data released by the International Energy Agency in 2023, due to the impact of the new crown epidemic, the carbon emission in 2020 will be reduced, but it will rebound to the pre-epidemic level in 2021.