A biosignal-based avatar control system according to an embodiment of the present disclosure includes an avatar generating unit that generates a user's avatar in a virtual reality environment, a biosignal measuring unit that measures the user's biosignal using a sensor, a command determining unit that determines the user's command based on the measured biosignal, an avatar control unit that controls the avatar to perform the command, an output unit that outputs an image of the avatar in real-time, and a protocol generating unit for generating a protocol that provides predetermined tasks, and determines if the avatar performed the predetermined tasks. According to an embodiment of the present disclosure, it is possible to provide feedback in real-time by understanding the user's intention through analysis of biosignals and controlling the user's avatar in a virtual reality environment, thereby improving the user's brain function and motor function.