叙述和介绍了采集交流信号的常用方法，指出了常用方法在采集幅度快速变化的交流小信号时存在的缺陷。在此基础上提出了一种新的交流信号同步采集方法，适合于对采样率和采集精度要求较高的场合。 Describes and introduces the commonly used method of AC signal acquisition, and points out the shortcomings of commonly used methods in the acquisition of AC small signal with rapidly changing amplitude. On this basis, a new synchronous acquisition method of AC signal is proposed, which is suitable for the occasions that require high sampling rate and acquisition accuracy.