In order to solve the problem that the signal generated by traditional “signal generator+power amplifier” cannot meet the demand of multichannel and square wave waveform of inchworm rotary driver, a signal controller was designed to generate multiple square waveforms by on-off of a Cmos control pulse module. The three driving signals obtained through this scheme were square wave current signals, which can avoid the occurrence of “frequency doubling” phenomenon in giant magnetostrictive materials. By setting the parameters such as the period, duty cycle and delay of the signal, the three-channel square wave driving signal with set timing can be output. According to the voltage law, the square wave was simplified to step wave. The current model of driving signal was established, and the parameters were identified. The current analytical formula can accurately represent the current signal within the operating frequency range. The experimental platform was built and tested, the experimental results showed that the square wave output by the signal controller was better than that by the traditional scheme in the working frequency range, and the set three-way signal can drive the inchworm rotary driver to generate step-by-step rotation motion. The angular displacement response of the rotating actuator was analyzed. By optimizing the timing of the driving signal, the maximum operating frequency of the rotary driver was increased from 160Hz to 210Hz.