A demand side response-based microgrid optimal unit and time-of-use electricity price optimization method. The method comprises the following steps: 1) acquiring supply and demand historical data of a microgrid, wherein the data comprises internal load data of the microgrid, a supply situation of distributed renewable energy and basic information of various types of energy supply units; 2) using the historical data to analyze outputs of various energy supply systems so as to analyze a supply and demand situation inside the microgrid; 3) setting an optimized target function subjected to distributed optimization; and 4) using a particle swarm optimization algorithm and an interior-point method to carry out optimized resolution. By means of the method, the supply situation of renewable energy of a microgrid and a demand side response under the excitation of time-of-use electricity price are organically combined, and an optimal unit combination of the microgrid and a time-of-use electricity price strategy are subjected to distributed optimization by means of a particle swarm algorithm and an interior-point method, so that the problems of excessive operating costs of the microgrid and excessive lack of internal loads are effectively relieved, ensuring that the electricity usage demands of a user are well met.