The energy and environment issues are common challenges facing the global automotive industry. The development of electric vehicle has become the strategy direction of China's automotive industry "Five" plan. The emerging electric car industry also is full opportunity for China's automotive technology to catch up with developed countries. The electric vehicle charger is an important part of electric vehicle, the technologies of advanced DC/DC converter, active power factor correction, harmonic suppression, high density magnetic integration, balanced current of parallel converter, communication between charger and battery management system (BMS) and fast charging are the keys for improving efficiency, power density, dynamic response, electromagnetic compatibility and reducing the size and weight of electric vehicle.