The invention relates to a battery pack discharge control method and control device based on a cascaded energy storage converter. The method comprises steps of: first determining the number of energy storage converters required to be bypassed in a battery pack; when the number of the energy storage converters required to be bypassed is less than or equal to 1, calculating an error value between the minimum voltage corresponding to the energy storage converter with the minimum voltage in the battery pack and the voltage of other energy storage converters; finally, when the absolute value of the error value between the minimum voltage and the voltage of other energy storage converters is greater than a set error threshold, performing PWM control on the converter device in the energy storage converter with the minimum voltage to perform PWM discharge on the energy storage device. The PWM control of the converter solves a problem that the inconsistency and the failure of an energy storage converter in the battery pack cause that the battery pack does not work normally, and achieves the overall control of the battery pack. Therefore, the discharge control method provided by the present invention can effectively perform discharge control on the battery pack.