This is actually a question of the choice of fluorescent whitening agents. From the practical use of many years, the best use of DSD acid di-triazines and stilbene-based biphenyl fluorescent whitening agents. Among them, C.I. Fluorescent Brightener 351 and C.I. Fluorescent Brightener 71 are widely used in various countries in the world, which is the fluorescent whitening agent CBS and fluorescent whitening agent CXT which are widely used in the detergent industry in China.