In modern scientific research and engineering practice, high -precision measurement of time interval between two or more physical events is often required. After years of development, there are currently many ways to measure a variety of high -precision time interval. If you implement different technologies, it can be divided into two categories: simulation and numbers. The simulation method is mainly to convert T to voltage by charging capacitance and then convert it into a digital amount through the modulus. However, the traditional simulation methods include the shortcomings of temperature sensitivity and long conversion time. Therefore, digital methods are generally used to achieve measurement. Common digital measurement methods include direct counting method, tap latency method, and cursor method. However, common measurement methods cannot meet actual needs. Therefore, this article relies on the FPGA platform to achieve a time interval measurement method with resolution to Ana second -level.