The invention relates to the field of energy utilization, in particular to a clean energy storage and seawater desalination co-production system and method. According to the invention, wind power, photovoltaic power generation, tidal power generation and ocean tidal current power generation are firstly adjusted through a power transmission and transformation system, then electric energy is transmitted to an electric steam device, the steam generated by the electric steam device is sent to an electrical power generation system to generate electricity so as to acquire good quality electric energy, at the same time the steam electrical power generation system falls into a first electrical power generation system and a second electrical power generation system, the electric energy of differentelectrical power generation systems can be supplied to different objects according to needs, thus increasing the flexibility of control. The invention effectively solve the problems of randomness andfluctuation of wind power, photovoltaic power generation, tidal power generation and ocean tidal current power generation, enable stable operation of the co-production seawater desalination system, improves the operation efficiency of the system and saves resources.