In distribution networks with a high penetration of photovoltaic (PV), a coordination between reactive power compensation (RPC) of PV inverter and active power compensation (APC) of battery energy storage system (BESS) is always used in voltage regulation (VR). Since using a periodical VR inevitably increases communication utilization, how to design a new event-triggered one to reduce communication burden while achieving comprehensive voltage governance with the required minimum BESS sizing? Therefore, an event-triggered hybrid VR method is proposed in this paper. Firstly, an event-triggered communication is designed based on the changes in bus voltage and sensitivity, thereby defining all operating instants into transmission and ordinary sampling types. For the voltage violation issue at the transmission instants, a network-wide coordinated proportional RPC-APC is then designed, which keeps constant during one transmission interval. For the additional voltage fluctuation at the ordinary sampling instants in the interval, a local RPC-APC is additionally designed to yield a fast suppression without using any communication. In addition, the required minimum BESS sizing is obtained by calculating the total APC for VR requirement, which gives a reference in configuring BESS. Finally, the case study is conducted to demonstrate the effectiveness of this method.