The invention discloses a low-cost electromobile self-help charging system and method. Hardware includes an intelligent charging device which comprises a standard charging interface adapter, a billing module and an authentication module. The system is simple in structure, convenient to mount and low in manufacturing cost. The system is arranged within a certain range of a parking space, authentication is performed automatically, mains supply is provided to an electromobile for charging through the standard charging interface adapter after authentication, charging service is billed automatically, payment is automatically completed after charging is finished, and the whole process is completed in a self-help manner without manual participation, so that the system is low in cost. The system is wide in application range, can be mounted basically in all places with parking spaces like commercial parking lots, free-of-charge parking lots, community parking lots and outdoor parking lots, is high in coverage rate and meets charging needs of users at any time; occupation of specific time of the users is not needed, so that time cost and personnel cost are lowered. The low-cost electromobile self-help charging system can realize multi-person sharing and self-help intelligence and meets the needs of the users.