Battery is a key component of Electric Vehicles (EVs), which has sparked a great demand for improvement in the EVs charging system. This paper proposes an integrated charging system for wireless power transfer (WPT), Onboard charger (OBC), and auxiliary power module (APM). The receiving coil on the secondary side can be weakly coupled with the transmitting coil of WPT and strongly coupled with the transmitting coil of OBC. Using a transformer on the receiving side to integrate the APM into the circuit. In this way, receiving coil, compensation network, and power electronics converter can be shared. The integrated structure can work in three working patterns. In the WPT mode and OBC mode, power grid delivers energy to the EV batteries, high-voltage (HV) batteries and low-voltage (LV) batteries can be charged at the same time. In the APM mode, HV batteries power LV batteries. In the traditional EV charger, WPT, OBC, and APM are three separate systems. This paper integrates three charging systems with the advantages of high-power density and cost effectiveness. The experimental results verify the proposal.