Power system load forecasting is one of the important projects in power system research, which plays a very important role in the normal operation and stability of power system. In order to have practical significance to the safe operation of power grid, the forecasting of load must be accurate and correct. This paper explains the characteristics of load forecasting, summarizes the types and significance of load forecasting and introduces several commonly used forecasting methods, and finally expounds the conclusion and future outlook of load forecasting.