A color carrier frequency offset estimation algorithm based on phase unwrapping and linear regression is disclosed, (1) providing the initial phase of color synchronized component of initial black level signals in a filed; adopting the black level signals at an initial place in the filed; the phase range obtained by the phase estimation being from 0 to 2Pi, there being five phases as frequency estimation; (2) using a phase unwrapping algorithm to unwrap the extracted phase; the phase unwrapping is that the phase at other four lines is adjusted in an unique linear range based on the phase at the first line; (3) using a linear regression model to fit the unwrapped phase, thereby extracting color synchronous frequency; determining the solutions of overdetermined equations by means of least square criterion; (4) using a limitr to limit the extracted color synchronous frequency. When the input is non-standard video signal, the color carrier frequency is estimated by means of the phase unwrapping algorithm and the linear regression model so as to improve the precision of the local color carrier and carry out digital high-definition demodulation.