A method for determining the lifespan of an LED lighting device, comprising: - placing a controller having time-keeping capabilities and a low voltage DC power source inside the LED lighting device, wherein the low voltage DC power source supplies power to the controller; - placing a light intensity sensor in a luminous zone of the LED lighting device, wherein the light sensor is connected to the controller; - by the controller, capturing illuminance data and converting the illuminance data into a luminous flux maintenance factor or sending the illuminance data to a display terminal; - when the power source is connected to power: a. the LED lighting device starts illuminating light, b. the controller starts to keep time data as recorded time simultaneously, and c. time data is obtained by the controller and stored in the controller or displayed on the display terminal, characterized in that the method comprises: - obtaining an initial record as the initial illuminance data record related to the LED lighting device when the LED lighting device is first turned on and has been on for 20-60 minutes of pre-heating; - transmitting the initial illuminance data record from the sensor to the controller simultaneously; - recording subsequent illuminance data records related to the LED lighting device when the LED lighting device has been on for each additional 20-30 minutes; - using a built-in program, the controller comparing the recorded subsequent illuminance data with the initial illuminance data, and converting the illuminance data records into a luminous flux and a luminous flux maintenance factor; - sending the luminous flux or the luminous flux maintenance factor to the display terminal to be displayed; and - determining the lifespan of the LED lighting device to be the recorded operation time, when the luminous flux maintenance factor drops below a threshold value when the illuminance data shows insufficient luminance. - placing a controller having time-keeping capabilities and a low voltage DC power source inside the LED lighting device, wherein the low voltage DC power source supplies power to the controller; - placing a light intensity sensor in a luminous zone of the LED lighting device, wherein the light sensor is connected to the controller; - by the controller, capturing illuminance data and converting the illuminance data into a luminous flux maintenance factor or sending the illuminance data to a display terminal; - when the power source is connected to power: a. the LED lighting device starts illuminating light, b. the controller starts to keep time data as recorded time simultaneously, and c. time data is obtained by the controller and stored in the controller or displayed on the display terminal, a. the LED lighting device starts illuminating light, b. the controller starts to keep time data as recorded time simultaneously, and c. time data is obtained by the controller and stored in the controller or displayed on the display terminal, - obtaining an initial record as the initial illuminance data record related to the LED lighting device when the LED lighting device is first turned on and has been on for 20-60 minutes of pre-heating; - transmitting the initial illuminance data record from the sensor to the controller simultaneously; - recording subsequent illuminance data records related to the LED lighting device when the LED lighting device has been on for each additional 20-30 minutes; - using a built-in program, the controller comparing the recorded subsequent illuminance data with the initial illuminance data, and converting the illuminance data records into a luminous flux and a luminous flux maintenance factor; - sending the luminous flux or the luminous flux maintenance factor to the display terminal to be displayed; and - determining the lifespan of the LED lighting device to be the recorded operation time, when the luminous flux maintenance factor drops below a threshold value when the illuminance data shows insufficient luminance.