Abstract: To assess the risk of cyber-attack, this paper constructs a bilayer assessment model of load redistribution attack risk based on game theory, introduces false data attacks and load redistribution attacks, and constructs a two-layer optimisation model for the risk of load redistribution attacks based on a game-theoretic approach.In addition, this paper uses the KKT condition to transform the bilayer model into a single-level mixed-integer linear programming model, and carries out and analyzes simulation experiments on the IEEE 14-bus system and the IEEE 30-bus system, to assess the risk of load redistribution attacks on the security and economic operation of the power system. In addition, this paper provides suggestion on how to prevent and defend against load redistribution attacks.