With the continuously improving requirement for data center power supply, resonant switched capacitor converter has been widely studied and applied due to its high efficiency and power density. In this paper, a high-performance cascaded switched-capacitor converter is proposed. Firstly, a detailed analysis is conducted on its working states under different modes. Secondly, through theoretical analysis, it has been confirmed that the coupling operation of two-stage circuits can be achieved under specific operating modes, thereby reducing the capacity requirement of decoupling capacitors and further improving the power density of the circuit. The experimental prototype can achieve a power density of 333 W/in³, peak efficiency of 97%, and full load efficiency of 95%.