The invention discloses a modular input series output parallel converter voltage-sharing control method based on communication; the input voltage reference value a formula which is as shown in the specification of a sub module m is updated in a communication mode, so that secondary adjustment of an input voltage-sharing ring can be realized, the output voltage adjustment rate is improved while theinput voltage uniform sharing is ensured, and the control effect is the same as that of the traditional centralized control. If the communication occurs, the input voltage reference value a formula which is as shown in the specification is switched to a preset value, so that input voltage uniform sharing and a certain output voltage adjustment rate can be realized, and the control effect is the same as that of the traditional upwarping and dispersing control. According to the method, the modular input series output parallel converter centralized control and dispersion control method are combined, so that the modularization degree is high, the reliability is high, the control effect is good, the expansion and the redundancy of the system are easy to realize, and engineering popularizationand application are facilitated.