The invention discloses a high precision digital-to-time converter (DTC) comprising a sequential circuit and a slope generation and threshold comparison circuit connected with each other. According tothe technical scheme, the mode of firstly discharging with fixed time and then charging with fixed current is used, so that delay time is independent of an absolute value of a charging-discharging capacitor, and is only related to a current proportion and an input frequency period. As the capacitance value changes largely along with PVT, and the current proportion and the input period are relatively accurate, compared with the traditional digital-to-time converter having the characteristic of high precision, the high precision digital-to-time converter can improve conversion accuracy and availability of the DTC.