The invention relates to the technical field of phase sequence test of three-phase alternating current, and discloses a simple and easy phase sequence test method of the three-phase power frequency alternating current. The method comprises the following steps: taking pulsatory direct current voltage signals of three phases A, B and C of the power frequency alternating current, performing timing sequence processing, converting the pulsatory direct current voltage into power single-point sampling digital signals at A, B and C time sequences in each period through a photoelectric isolation device; and judging phase sequences of three-phase current A, B and C through an identification circuit time sequence trigger, when the square wave digital signals accessed into the three phases A, B and C are in a positive sequence, an LED (light-emitting diode) is normally on, and when in a negative sequence, the LED is normally off. According to the invention, the three-phase current half wave can be shaped to be standard triggering level; the method can further facilitate phase sequence indication, messed sequence protection and missing sequence protection; and at the same time, the method can be used for testing the three-phase power at different frequencies.