Flexible HVDC system is very suitable for offshore wind farm grid-connection, but when traditional AC-DC power flow algorithm is used to calculate the power flow of grid-connected wind farm based on VSC-HVDC, once removing the DC system, the wind farm becomes isolated communication node, thus the Jacobi matrix of communication system will not be irreversible and iterative process can't be continued. Aiming at these defects, this paper proposes a AC/VSC-HVDC power flow decoupled algorithm containing VSC-HVDC, by which the AC system and DC system are decoupled and computed iteratively. This algorithm overcomes the shortages of existing AC/DC hybrid system power flow calculation algorithm, such as bad inheritance to AC power flow calculation program, much expansion variables, slow calculation speed, and so on, and solves the problem of wind farm VSC-HVDC grid-connected system power folw algorithm. Calculation of standard examples verify that the proposed algorithm is valid and can be used for steady-state power flow analysis of wind farm DC grid-connected system.