A digital musical score instrument and its automatic sheet-turning method, comprising an audio acquisition module, a video acquisition module, a switch, a memory, a processor, a sound output device and a display, and the signal output terminals of the audio acquisition module, the video acquisition module and the switch are all connected with the processing The corresponding signal input end of the processor is connected, the storage signal end of the processor is bidirectionally connected with the memory, the signal output end of the processor is connected with the signal input end of the display, and the audio signal output end of the processor is connected with the sound output device. The present invention has multiple functions such as music score playback, automatic score turning, metronome, accompanying training error correction, recording, storage retrieval, and musical score zooming in and out, among which automatic score turning, accompanying training error correction and metronome functions are the main features of the present invention.