With large-scale power grids going highly-capacitive， close-coupled and sophisticated， automatic voltage control（AVC） is getting increasingly difficult as can be seen in control mismatch problems between multi-level dispatch centers in engineering practice. The principal manifestations， causes and harm of multi-level voltage control mismatch in large-scale power grids are summarized. Based on an analysis of the essence and mechanism of multi-level voltage control mismatch in large-scale power grids， a game model is presented to describe the problem of multi-level voltage control mismatch. A case study on Nash equilibrium and cooperative game analysis for AVC is employed to show that its advisable to explain the mismatch mechanism of voltage control and solve the mismatch problem via game modelling.