The invention discloses a system for measuring electromyographic signals of deep muscles based on sEMG, comprising: a measuring electrode, an EMG signal collector and a data processing device wherein the measuring electrode is a monopolar needle electrode or a fine-wire electrode, the EMG signal collector is connected to the measuring electrode to collect the measured EMG signals therefrom and the data processing device is connected to the EMG signal collector for acquiring parameters corresponding to sEMG on the basis of the collected EMG signals. According to embodiments of the present invention, the electromyographic activity of a single targeted muscle and a deep muscle can be detected by replacing existing surface electrodes with monopolar needle electrodes or fine-wire electrodes, and thereby limitations that surface electrode recordings are restricted to superficial muscle groups underneath the electrodes can be eliminated.