时间继电器是指当加入（或去掉）输入的动作信号后，其输出电路需经过规定的准确时间才产生跳跃式变化（或触头动作）的一种继电器。是一种使用在较低的电压或较小电流的电路上，用来接通或切断较高电压、较大电流的电路的电气元件。同时，时间继电器也是一种利用电磁原理或机械原理实现延时控制的控制电器。它的种类很多，有空气阻尼型、电动型和电子型等。
The time relay refers to a relay that produces a skip change (or contact action) when the output circuit is required to pass the prescribed accurate time after adding (or removing) the input action signal. It is a kind of electric component which is used to connect or cut off high voltage and high current circuit. At the same time, the time relay is also a kind of control equipment which realizes the delay control by electromagnetic principle or mechanical principle. There are many kinds of air damping, electric and electronic.