The input series output parallel (ISOP) converter system faces the challenge of complex input power balancing control. In this article, a switched capacitor based multi-port DC converter with power self-balanced capability is proposed. Based on the switched-capacitor principle, the input capacitors periodically charge and discharge the balancing capacitors to balance the voltage of the input capacitors. Furthermore, by introducing LC coupling circuit, the impedance of each branch is adjusted to balance the current of switch. Finally, the simulation of 3kV input, 800V/1kW and 80V/1kW output is performed. Simulation results show that the current of each switch is self-balanced, and the voltage of each input capacitor is self-balanced. Each output port is independent of each other and has different voltage levels. A 1.5kV/720W laboratory prototype is built to validate the effectiveness and practical feasibility of the proposed topology.