A Wireless Sensor Network (WSN) security strategy is imperative to counteract security threats, and energy consumption directly affects the network life-time of a wireless sensor; thus an attempt to exploit a low-consumption Intrusion Detection System (IDS) to detect malicious attacks makes a lot of sense. Current Intrusion Detection Systems can detect just some specific attacks and the network life time is reduced due to their high energy consumption. For the purpose of energy limitation and high efficiency, this paper proposes an intrusion detection model based on game theory and an autoregressive model. The paper not only improves the autoregressive theory model to a non-cooperative complete information static game model, but makes a prediction about attack pattern based on the reliable model. The proposed approach improves on previous approaches in two main ways: it takes energy consumption of the intrusion detection process into account, and it obtains the optimal defense strategy, balancing detection efficiency and the system's energy consumption by analyzing the model's mixed Nash equilibrium solution. In the simulation experiment, the running time of the process is regarded as the main indicator of energy consumption of the system. The simulation results show that the IDS proposed not only effectively predicts the attack time and the next targeted cluster based on the game theory, but also reduces energy consumption.