The invention discloses a smart watch based on action recognition and an action recognition method. The smart watch comprises a circuit control unit and a watch shell carrier body, wherein the circuit control unit comprises an action sensor group, a central processing system, a command execution module and a display screen, and a user can operate the smart watch by virtue of the action of the forearm of a human body. The invention also relates to an operating method based on the smart watch. The operating method comprises the steps: setting a recognizable gesture action command; taking a special front arm gesture action by the user; collecting the action information by virtue of the action sensor group; processing the action information by virtue of the central processing system, and analyzing the operating gesture of the user; carrying out the operation confirmation on a complicated action; executing the corresponding function operation by virtue of the command execution module, and displaying an execution result on the display screen, so that the error in operation of the human-machine interaction can be reduced.