The invention belongs to the technical field of detection methods and more specifically relates to a correlation analysis based zero crossing point detection method. The method includes concrete steps of (a), measurement on power grid operation voltage signal U(t) is performed; (b), after step (a), randomly cutting out 50 cycles of the voltage signal U(t) and generating a standard cosine signal cos(wt) in operation, correlation calculation is performed on the standard cosine signal cos(wt) and the collected voltage signal U(t) and a calculation result A(t) is obtained; when integration is performed on the 50 cycles, an integral value containing double fundamental wave term is zero; (e) performing integration on the 50 cycles and making U0 known, the initial phase angle Theta0 of a cut-out moment can be calculated through correlation analysis; (f) after step (e), by utilizing the working cycle of power grid operation is a fixed value and one cycle has two zero crossing points and setting the signal cut-out moment as t0, calculating the zero crossing point t00. By adopting the method provided by the invention, the structure of a phase control circuit breaker is simplified; filtering treatment is not needed during a zero crossing point detecting process and the precision of the zero crossing point obtained by adopting the method provided by the invention is high.