The present invention provides a method and apparatus for controlling a light-emitting device of a digital keyboard musical instrument. The method includes: detecting a touch action generated by a user upon a key of the digital keyboard musical instrument and generating a touch signal, by a sensor placed underneath the key, and transmitting the touch signal to a processor, wherein the touch signal comprises the magnitude information of the touch action; receiving the touch signal and generating a corresponding control signal in accordance with the magnitude information of the touch signal, by the processor; and actuating the light-emitting device to produce a light-emitting effect in accordance with the control signal by the processor. Since the detection of the touch action upon the key by the sensors is accurate enough to capture all details of the complete key-touching action, the light-emitting effect produced based on this more detailed detection of the touch action is more exquisite and accurate.