The invention discloses a musical performance auxiliary system which comprises a command and control panel and performer terminals. The command and control panel and the performer terminals are connected through a network, and are used for displaying a main score of an electronic musical score and branch scores of the electronic musical score respectively. Both the command and control panel and the performer terminals comprise display devices, user input devices, master control devices and communicating ports. The master control device of the command and control panel is used for controlling the score turning operation of the main score, and meanwhile, broadcasting the bar number on the page heading of the main score after score turning in the network. The master control device of the performer terminals is used for comparing the bar number received from the network with the bar number of the page heading of a next page of the branch scores of the main score, and when the bar number received is larger than the bar number of the page heading of the next page of the branch scores, controls the branch scores to conduct score turning. The double-page display mode and the relevance between bar numbers of the main score and bar numbers of the branch score are utilized in the musical performance auxiliary system, collaborative score turning of the main score and the branch scores is realized during band performance and rehearsal, a musical score pre-turning function is achieved, therefore, a conductor or the performance can read the score continuously and not be disturbed, and the improvement of the performance level is facilitated.