A current sharing control strategy for paralleled power system is presented based on half-bridge three-port converter (HB-TPC). To realize the current sharing of the system, current sharing control should be applied to more than two ports simultaneously, and then the third port achieves current sharing naturally. To simplify the close-loop design, decoupling variables are employed and bandwidth of the multiple control loops is set far away to decouple the converter approximatively. To obtain the higher stability and better current equalization degree, a structure with the current sharing outer-loop and voltage regulation inner-loop structure is adopted, and parameters of the control loops are designed optimally. A 200 W HB-TPC prototype is selected as the module to build the paralleled power system. Finally, the analysis and design are verified by experimental results.