提出了一種基于電容器充放電原理的雙擴展內(nèi)插法，研究了雙擴展測時內(nèi)插器的工作原理和誤差分析。雙擴展內(nèi)插法與單擴展內(nèi)插法相比，能大大提高測時分辨力，并顯著減少其內(nèi)插時間，有效地解決了單擴展內(nèi)插法中高測時分辨力和快測量速率之間的矛盾。This paper proposed a double stretch interpolation method based on the charge and discharge principles of the capacitors, and studied the working principles of the double stretch time measurement interpolator and its error analysis. The double stretch interpolation method is able to greatly increase the time measurement resolution and reduce the interpolation time comparing with the single stretch interpolation technique. Therefore, the conflict between the high time measurement resolution and rapid measurement speed of the single stretch interpolation method is solved efficiently.