The invention discloses a method, a device and a system of determining a phase and electronic equipment. The system comprises an input interface, a switch circuit and an output interface. The input interface is used for acquiring the first power supply signal of a first power supply and the second power supply signal of a second power supply. The switch circuit located between the input interfaceand the output interface is used for determining the trigger state of a plurality of parallel silicon controlled rectifiers based on the second power supply signal, and determining an output voltage value according to the first power supply signal and the trigger state of the silicon controlled rectifiers. Under the condition that the output voltage value is a preset voltage value, the phase of the first power supply and the phase of the second power supply are determined to be consistent. The output interface is connected to the switch circuit and is used for outputting the voltage value. Inthe prior art, an operation for determining whether the phases of the double power supplies are consistent is complex. In the invention, the above technical problem is solved.