[Objective] The large-scale integration of high-penetration electric vehicles （EVs） into distribution networks inevitably causes voltage fluctuation issues. To solve this problem， this paper proposes a collaborative method for optimal configuration of multi-type vehicle-to-grid （V2G） chargers and coordinated voltage quality improvement of distribution networks. [Methods] This paper establishes a bi-level collaborative optimal scheduling model for charging stations that incorporates the reactive power response characteristics of the residual capacity of multi-type V2G chargers. The upper-level model aims to minimize the annual power purchase cost of EVs and the investment cost of chargers， realizing the collaborative optimization of charging strategies and charger type selection. The lower-level model takes the minimum voltage deviation at the point of common coupling （PCC） of charging stations as the optimization objective， and adopts the residual capacity of chargers to implement reactive power voltage regulation. The bi-level model achieves efficient collaborative operation via active-reactive power decoupling and iterative correction of constraint boundaries. [Results] Simulation results demonstrate that the proposed model can reduce the comprehensive operational cost and effectively improve the voltage profile of distribution networks， with a maximum node voltage quality improvement of 40.46% during peak electricity price periods. [Conclusions] The proposed model well balances the economic benefits of EV charging and the voltage safety of power grids. It verifies the feasibility of V2G chargers in realizing the dual functions of charging service and grid auxiliary support， providing a novel technical solution for chargers to participate in grid ancillary services.