The invention relates to a power-frequency phase detection circuit corresponding to partial discharge pulse in partial discharge measurement, and the circuit comprises the following modules: a voltage transformation module, a low-pass filtering module, a waveform shaping and transformation module, a phase lock frequency multiplication module and a counter module; wherein the voltage transformation module can perform voltage reduction on a voltage signal of a power-frequency power supply to become a low voltage signal and is used for following signal input, the low-pass filtering module is used for eliminating high-frequency interference, the waveform shaping and transformation module is used for shaping an inputted sinusoidal signal by using a comparator and transforming the sinusoidal signal into a square signal, the phase lock frequency multiplication module is used for performing frequency multiplication on an input signal with frequency of f1 for N times, so that the output frequency of a phase-locked loop is Nf1, and the counter module is used for counting the output of a frequency multiplier by using a binary counter, so that a count value of the pulse is processed to obtain a phase value. According to the invention, the acquirement of the partial discharge pulse power-frequency phase is achieved, and the phase precision is improved.