The invention discloses a temperature compensation crystal oscillator based on a digital circuit and employs a closed loop compensation framework to realize high precision compensation of the crystal oscillator. Firstly, a power divider is employed to divide a required frequency signal outputted by the temperature compensation crystal oscillator into two paths, one path is outputted, the other path is transmitted to an analog-to-digital converter and converted into a frequency value in a binary coding code and is then returned to a micro processor, through a pre-stored frequency value-compensation voltage value binary coding table, a required compensation voltage value can be queried, secondly, based on the compensation voltage value, a required compensation voltage is generated by the compensation network, a voltage-controlled voltage control end of a voltage-controlled crystal oscillator is made to output the stable required frequency signal, and temperature compensation is finally realized. A problem of the temperature retardation effect caused by employing a temperature sensor in a temperature compensation crystal oscillator in the prior art and an error problem caused by inconsistency between sensor temperature and real-time crystal temperature can be solved.