In 2021, due to the impact of the rise in coal prices, the coal price and electricity price in the power market of Guangdong Province were inverted, which eventually led to large-scale power blackouts and power rationing in Guangdong Province. This event reflects that the price of thermal coal is an important factor affecting the stable operation of thermal power enterprises and even the spot market of Guangdong Province. Therefore, based on vector autoregression (VAR) model and impulse response test, this paper analyzes the long-term dynamic cointegration relationship between port thermal coal price and thermal power side spot price, and finally establishes a thermal power side spot price prediction and early warning system with port thermal coal price monitoring as the core, so as to provide suggestions for the development of power spot market in Guangdong Province.