In order to measure frequency, amplitude and phase angle of fundamental current real-time and effectively, a fundamental current instantaneous value detection and synchronized current phasor measurement algorithm is proposed. Zero sequence voltage and instantaneous current are considered as phase-a component in three-phase system, phase-b and phase-c current and voltage can be constructed based on positive sequence and symmetrical principle. Synchronous reference frame transformation can be applied for calculation of fundamental zero sequence instantaneous current value, as well as positive and negative sequence instantaneous current value. Fundamental current phasor can be finally calculated by the proposed frequency, phase and magnitude algorithm. The proposed algorithm can improve the accuracy and response performance of phasor measurement when the power system is in a dynamic process. Simulation results verify the correctness and validity of the proposed algorithm.