A LED illumination device and validation methodology of LED illumination device's lifespan, comprises a controller, timing chip and low-voltage DC power supply, the controller is connected to the display terminal, the timing chip is positioned inside the LED illumination device, so as to get real-time recording of the operating time of the LED illumination device which is transmitted to the display terminal for display; meanwhile, a light sensor is placed in the luminous zone to obtain luminosity data so as to measure real-time luminous maintenance rate. When the measured luminous maintenance rate gets lower than the luminous maintenance rate predetermined for critical lifespan, the operating time recorded by the LED illumination device at this moment is the lifespan of this LED illumination device.