In this paper, a spectrophotometer is designed. The xenon lamp is used as the measuring light source of the spectrophotometer, and a mechanical structure is designed to adjust the proportion of ultraviolet energy in the luminous intensity of xenon lamp. The standard color plate determined by the proportion of fluorescent substances is used as the standard substance to calibrate the instrument and the standard instrument. The algorithm is designed to modify the instrument light source to make the ultraviolet spectral radiation intensity of the illumination light source is consistent with that of the standard instrument, so as to reduce inter-instrument agreement. In addition, experiments are designed to verify the effect of the scheme. The maximum value and average value of inter-instrument agreement ΔE_ab of non-fluorescent materials measured by instruments without the proposed scheme are 0.88 and 0.44 in CIELAB uniform color space, and that in the situation with fluorescence color are 13.69 and 3.46. After applying the proposed scheme, the maximum value and average value of inter-instrument agreement ΔE_ab of non-fluorescent materials measured by instruments are 0.88 and 0.38 in CIELAB uniform color space, and that in the situation with fluorescence color are 3.88 and 1.04. The experimental results show that the proposed scheme can improve the inter-instrument agreement level of fluorescent color measurement between different instruments.