Abstract: This paper introduces a 16-channel multimodal high-precision transcranial electrical stimulation system specifically for non-invasive brain stimulation. This system added TMCS mixed stimulation mode with TACS, TDCS, TPCS and TRNS. By designing a compensated high precision constant current source, the constant stimulation current with an accuracy of 0.03 mA in the range of ± 2 mA and the stimulation frequency of 50－200 kHz with low frequency of 0－4 kHz (high frequency of 0－0.1 Hz) are realized. In TACS stimulation mode, there are five adjustable wave forms: triangular wave, sine wave, sawtooth wave, square wave and mixed wave. The system has dual closed-loop control overcurrent detection and simultaneous real-time electrode contact impedance detection. After relevant tests and verification, the system has good stimulation accuracy, high safety and reliability. Compared with the existing products at home and abroad, the cost is lower, the stimulation mode stimulation waveform is richer, and has a certain market application value.