Abstract: Due to the popularity of intelligent mobile devices, malwares in the internet have seriously threatened the security of industrial control systems. Increasing number of malware attacks has become a major concern in the information security community. Currently, with the increase of malware variants in a wide range of application fields, some technical challenges must be addressed to detect malwares and achieve security protection in industrial control systems. Although many traditional solutions have been developed to provide effective ways of detecting malwares, some current approaches have their limitations in intelligently detecting and recognizing malwares, as more complex malwares exist. Given the success of machine learning methods and techniques in data analysis applications, some advanced algorithms can also be applied in the detection and analysis of complex malwares. To detect malwares and consider the advantages of machine learning algorithms, we developed a detection framework for malwares that threatens the network security of industrial control systems through the combination of an advanced machine learning algorithm, i.e., reinforcement learning. During the implementation process, according to the actual needs of malware behavior detection, key modules including feature extraction, policy, and classification networks were designed on the basis of the intelligent features of reinforcement learning algorithms in relation to sequence decision and dynamic feedback learning. Moreover, the training algorithms for the above key modules were presented while providing the detailed functional analysis and implementation framework. In the application experiments, after preprocessing the actual dataset of malwares, the developed method was tested and the satisfactory classification performance for malware was achieved that verified the efficiency and effectiveness of the reinforcement learning-based method. This method can provide an intelligent decision aid for general malware behavior detection.