A personal training system assisted by artificial intelligence (AI) has a personal training device and a control device. The personal training device includes a jacket and pants, and houses sensors at positions corresponding to a user’s main muscle groups for monitoring the user’s movement posture and muscle activity of the main muscle groups. The control device has a data preprocessing unit for processing detected-signal data of the sensors, a training analysis device for executing an AI algorithm to conduct fatigue analysis of the user’s movement based on the user profile and the detected-signal data, and to make training load recommendations. The personal training system can simultaneously monitor posture, muscle activity and muscle fatigue in real time during the exercise; and use the AI algorithm to evaluate exercise performance and provide real-time feedbacks to improve the exercise and training efficiency, and reduce the risk of injury.