The invention relates to a modular charging/discharging system of a power battery pack of a multifunctional electromobile, which aims to provide a system which can effectively meet the requirement for the bi-directional power transmission of a charging station and can exert the functions of peak clipping and valley filling as well as peak modulation and frequency modulation of a power grid. The technical scheme is as follows: the modular charging/discharging system of the power battery pack of the multifunctional electromobile comprises a charging-station monitoring system and an information management system, wherein the charging-station monitoring system is composed of a computer and a network communication system. The modular charging/discharging system is characterized by also comprising a three-phase step-down transformer, wherein the high voltage side of the three-phase step-down transformer is connected with a power grid, and the low voltage side of the three-phase step-down transformer is connected in parallel with a plurality of charging/discharging branches; each branch comprises a three-phase distribution transformer and a charging/discharging module, and the three-phase distribution transformer is connected in series with the charging/discharging module; and each charging/discharging module comprises a pulse-width modulation alternating current/direct current (PWM AC/DC) converter with the function of bi-directional power transmission, a plurality of electromagnetic isolation type DC/DC transform modules with the function of bi-directional power transmission and the information management system, and the electromagnetic isolation type DC/DC transform modules are connected in parallel.