An ultrasonic scalpel, an energy instrument for surgical use, and a control method therefor; the scalpel including a handheld component and a control module; the handheld component provided with a trigger button. The trigger button is connected to an input terminal of the control module; the control module is electrically connected to an energy generating apparatus; and, if the trigger button is pressed, then the control module controls the energy generating apparatus to output ultrasonic energy, and, if the trigger button is released, then the control module controls the energy generating apparatus to stop outputting ultrasonic energy. In response to a first trigger signal triggered by an external switching action, each time the trigger button is pressed, the energy generating apparatus changes the current energy output state, the changed energy output state being maintained until the trigger button is pressed again.