In the context of China’s electricity market reform, the effective integration of mid-to-long-term and spot markets is studied in depth. Firstly, the composition of the electricity market system is outlined, and the main points of convergence between mid-to-long-term and spot markets in terms of trading, scheduling and settlement are analyzed. On this basis, a series of integration mechanisms are proposed, including the mid-to-long-term curve decomposition mechanism, the physical security guarantee mechanism and the price linkage mechanism. The effectiveness of the proposed mechanisms in actual operation is verified through the analysis of arithmetic examples. Finally, a coordination scheme between mid-to-long-term and spot markets is proposed, aiming at promoting the complementarity of the two markets and realizing the smooth operation and sustainable development of the electricity market.