The invention provides a DC/DC converter and an equilibrium control method for direct-current bus voltage in the DC/DC converter. The equilibrium control method is characterized in that a direct-current voltage deviation controller, a neutral-point potential controller, a constant-power controller and a constant-voltage floating charge controller, the direct-current voltage deviation controller, the neutral-point potential controller, the constant-power controller and the constant-voltage floating charge controller are coordinated to perform control, the output quantity of the direct-current voltage deviation controller is used as the current instruction value used for generating a PWM wave to control the on and off of a switch tube, and the equilibrium control of the direct-current bus voltage in the DC/DC converter. By the method precise in control, system stability can be kept.