The results show that even in the most extreme cases, when leds are placed before and after the detector opening, the peak luminous flux results are less than 5%. This is a very good test result. In the actual testing process, the repeated error of LED light flux measurement is far less than 0.1%. It can be seen that the test results of LPCE-2 test system are reliable and stable, which can provide a reliable guarantee. This standard system not only greatly supports LED research and development and production, but also is an ideal choice for optical performance measurement in the LED industry.