The invention relates to a method and system for performing frequency measurement according to a zero initial phase reference sine function sequence. The method includes the steps of: obtaining a real frequency mixing sequence and an imaginary frequency mixing sequence, then performing digital filtering and integration on the real frequency mixing sequence and the imaginary frequency mixing sequence, obtaining a real frequency integral value and an imaginary frequency integral value, obtaining the phase of a zero initial phase reference sine function modulation sequence according to the real frequency integral value and the imaginary frequency integral value, and obtaining the frequency of an electric power signal according to the phase. Obtaining the frequency of the electric power signal through the method provided by the invention can remarkably improve the degree of accuracy of frequency measurement of the electric power signal.