A voltage control method and system for distributed photovoltaic clusters are provided. The method includes the following steps: acquiring the reactive power regulation capability and active power regulation capability of a distributed photovoltaic cluster; dividing the distributed photovoltaic cluster based on the acquired reactive power regulation capability and active power regulation capability; and carrying out voltage control based on the photovoltaic cluster after division. The voltage regulation capability can be obtained according to the voltage regulation capability index of the cluster. It is ensured that each cluster has sufficient active and reactive power regulation capability to cope with the voltage change in the cluster. The active and reactive power outputs of distributedphotovoltaic in the cluster can be coordinated. The voltage change at the grid connection point of photovoltaic can be quickly responded to, and the level of grid voltage can be quickly regulated.