The invention relates to a design method of a dye formula. After the variety of each dye in the target dye formula is determined, the percentage of the mass of each dye accounting for the total mass of the dye is generated randomly to obtain a plurality of candidate dye formulas, and then, one candidate dye formula is screened out from the multiple candidate dye formulas; in the screening process,firstly, the percentages of the mass of the dyes accounting for the total mass of the dyes in the candidate dye formulas are input into one BP neural network model at the same time, the model outputsa K0 value of each dye in the candidate dye formula, then, a Dmax is calculated, Dmax=|K0max-K0min|, K0max and K0min are the maximum value and the minimum value of the dye K0 value in the candidate dye formula, finally, the Dmax of each candidate dye formula is compared, the candidate dye formula with the minimum Dmax is found, and the BP neural network model is a BP neural network trained by a plurality of historical dye formulas. The method is simple, and the compatibility of the obtained dye formula is good.