A system and a control method of a mobile micro-grid are provided. The mobile micro-grid system includes a renewable energy source and a non-renewable energy source which are in a container. The control method includes supplying the renewable energy source as a primary power supply to an external load; and determining whether the electricity of the renewable energy source is sufficient. If the electricity of the renewable energy source is sufficient, then the renewable energy source provides electricity to the external load; if the electricity of the renewable energy source is not sufficient, then the renewable energy source and non-renewable energy source provide electricity to the external load. If an external power source, which is a renewable-energy-type power source, is connected to the mobile micro-grid system, then the renewable energy source and external power source work as the primary power supply.