Abstract: In recent years, the miniaturization and low power consumption of underwater communication nodes become the difficult points of engineering design in deep-water exploration. The power amplifier driven by SPWM signal is widely used in underwater acoustic communication. Traditional SPWM generation system requires high complexity of circuit. Therefore, according to SPWM generation principle and circuit implementation, this paper presents a pulse sampling based SPWM generation method and analyzes its performance. And in this paper, a high efficiency SPWM generator based on digital processor is designed under the premise of ensuring less loss of SPWM information to reduce the area of hardware analog circuits. The experimental results show that the proposed pulse sampling method and high efficiency generation system can satisfy the engineering application.