To help the forecast of cold weather activity, the cold weather process in the North China from October 20 to 23, 2020 was analyzed by the methods of utilizing statistical analysis, such as composite, differential analysis and correlation analysis, and by using the data from the National Meteorological Information Center of China, the National Climate Center of China and the NECP data from NOAA Physical Sciences Laboratory. The results show that: 1) the cold air started from Siberia, took the east path to move southward, and finally affected most part of North China. 2) Almost no obvious weather occurred during the process. 3) The cold air mainly moved along with the form and development of the trough and ended when the trough got weaken.