Deadtime is the time period during which a detector processes the previous photon event and any later events will be ignored, thus the calculation of deadtime is of great importance to reconstruct the incident photon flux from the recorded counts. The High Energy X-ray telescope (HE) on-board the Insight-HXMT satellite records the deadtime only for a fixed time bin (i.e. 1 s), therefore it is impossible to directly obtain the deadtime for an arbitrary time interval, especially for high-energy transients much shorter than one second. Based on the electronics model of HE, we establish a deadtime calculation method to derive the deadtime in any time interval. We apply this method to transient sources observed by HE, including Gamma-ray Bursts (GRB) and Terrestrial Gamma-ray Flashes (TGF). Furthermore, since the data processing capacity of HE electronics is limited, HE suffers data saturation for very bright GRBs. During the saturation period, a significant part of counts signal cannot be recorded. We find that the amount of lost counts can be estimated by comparing the recorded 1 s deadtime and the calculated deadtime using the method mentioned above.

死区时间是检测器处理前一个光子事件而以后的事件将被忽略的时间段，因此死区时间的计算对于根据记录的计数重建入射光子通量非常重要。Insight机载高能X射线望远镜（HE）-HXMT卫星仅记录固定时间段（即1 s）的停滞时间，因此不可能直接获得任意时间间隔的停滞时间，尤其是对于短于一秒的高能瞬变。基于HE的电子模型，我们建立了一个停滞时间计算方法，以得出任何时间间隔内的停滞时间。我们将此方法应用于HE观测到的瞬变源，包括伽玛射线暴（GRB）和地面伽玛射线闪光（TGF）。此外，由于HE电子设备的数据处理能力有限，因此，对于非常明亮的GRB，HE会遭受数据饱和。在饱和期间，无法记录计数信号的很大一部分。