Reinforcement leing (RL) algorithm has been introduced for several de-cades, which becomes a paradigm in sequential decision-making and control. The de-velopment of reinforcement leing, especially in recent years, has enabled this algo-rithm to be applied in many industry fields, such as robotics, medical intelligence, and games. This paper first introduces the history and background of reinforcement le-ing, and then illustrates the industrial application and open source platforms. After that, the successful applications from AlphaGo to AlphaZero and future reinforcement leing technique are focused on. Finally, the artificial intelligence for complex inter-action (e.g., stochastic environment, multiple players, selfish behavior, and distributes optimization) is considered and this paper concludes with the highlight and outlook of future general artificial intelligence.