本文从使用者的角度介绍了超导量子干涉器件的原理。利用这种器件可望测量极弱磁场(10~(-11)G)及极弱电压(10~(-15)V)。文中介绍了它在电磁测量中的几个典型应用:磁强计、电压计及电流比较仪。 This paper introduces the principle of superconducting quantum interference device from the user’s point of view. It is expected to measure very weak magnetic field (10 ~ (-11) G) and very weak voltage (10 ~ (-15) V) with this kind of device. This article describes some of its typical applications in electromagnetic measurements: magnetometers, voltmeter and current comparator.