Abstract: The rescue for broken-down vehicles is becoming increasingly important with the increasing quantity of electric vehicles. Considering the situation of the shortage and unbalanced distribution of charging facilities, , a design of charging system for mobile charging vehicle is proposed and verified especially aimed at the reality of lacking mobile charging rescue facilities. The charging system consists four parts including the power generator, the power supply before DC bus, the integrated AC-DC charger and the large capacity energy storage battery. The safe and green charging system can be flexibly applied to various types of electric vehicles with a good compatibility.