The invention discloses a circuit electric energy quality optimizing device and method based on WIFI communication and a system. The system comprises a controller, a WIFI communication unit, an intelligent terminal, a display unit, an SVG power unit and a capacitor compensation unit. The WIFI communication unit and the controller are in wireless communication, and the controller controls the SVG power unit and the capacitor compensation unit to optimize electric energy quality by detecting circuit voltage or current. The problems of three-phase imbalance of a low-voltage circuit and low reactive compensation precision and the problems about harmonic waves in the system and system voltage stabilization are solved; meanwhile, device data interaction and state control can be met in the installation site, and the device is more convenient to control and debug and more economical under a circuit rod.