针对传统矿井瞬变电磁仪易受井下人文干扰因素的影响，设计了一种矿用孔中瞬变电磁仪；仪器的发射部分主要由电桥电路、消隐电路组成；为缩短关断时间，源栅之间的稳压二极管和发射线圈两侧吸收消隐电路构成快速关断电路系统，快速释放射线圈中的能量，削弱电感效应；接收部分具备全空间信号采集能力，通过自调节二次场信号的增益倍数，使设备动态范围满足需求。试验表明：该仪器具备探查钻孔径向含水异常体的能力，由于装置位于孔中，距探测目标体近，易获得信噪比高的二次场信号，并避免了巷道人文干扰因素的影响，提高了探测精度。

In view of the traditional mine transient electromagnetic instrument is easy affected by the underground human interference factors, a kind of mine in-hole transient electromagnetic instrument is designed. The transmitting part of the instrument is mainly composed of bridge circuit and hidden circuit. In order to shorten the turn-off time, the voltage regulator diode between the source and gate and the absorption and blank-elimination circuit on both sides of the transmitting coil constitute a fast turn-off circuit system, which quickly release the energy in the transmitting coil and weaken the inductance effect. The receiver part has the ability of full space signal acquisition, and the dynamic range of the device meets the needs by self-adjusting the gain multiple of the secondary field signal. The test show that the instrument have the ability to probe drilling radial water cut abnormal body, because the device is located in the hole, close to target body, easy to obtain high signal-to-noise ratio of the secondary field signal, and avoid the influence of human interference factors of roadway.