To solve the information security defense strategy selection problem, we established a non-cooperation and non-zero attack-defense game model, for the attacker and the defender has the features of confrontational goal, strategy dependence and non-cooperative relations. An improved quantization benefits and calculation method is proposed in the model, which can calculate the game equilibrium more accurately including the consideration of the defender counterattack payoff. By analyzing game equilibrium of the mixed strategy, the attack action can be predicted effectively under the assumption of rational. On the basis of the attack prediction, the security and defense strategy selection algorithm is designed and it is possible to select the optimal defense strategy against the threat of attack. The instance analyzing verified the validity of the model and method.