In microgrid systems, inverters typically adopt droop control strategies to compensate for voltage fluctuations. However, traditional droop control and its improved variants are incapable of identifying and responding to system faults caused by risk events. This paper proposes a centralized secondary voltage control strategy for islanded microgrids based on risk-averse model predictive control (MPC), aimed at enhancing voltage restoration capabilities. The proposed approach maintains high robustness in scenarios characterized by low probability but high impact. By embedding risk-aware mechanisms into the MPC framework, each distributed generation (DG) unit in the microgrid is able to communicate bidirectionally with a central controller via a communication network. When voltage deviations occur due to risk-induced events, the proposed strategy enables rapid response and voltage recovery. Comprehensive simulations conducted on a microgrid model developed in MATLAB/Simulink validate the effectiveness of the proposed control approach.