Taking account of the product diversity, a high-speed LED photochromic parameters measurement system was designed and fabricated. The fixture of the system can be adjusted to fit all kinds of chip. In order to improve the measurement accuracy and speed of dominant wavelength, a zoning look-up table method was proposed to calculate the dominant wavelength through the color coordinate. The test results showed that the proposed system can effectively improve the efficiency and accuracy of LED photochromic parameters measurement system.