In order to study the quality changes during the boiling process of green chilli sauce and to construct a relevant colour protection model， three colour protection agents， namely disodium hydrogen phosphate(A)， zinc gluconate (B) and sodium D-isoascorbate (C)， were selected for the colour protection test， taking chlorophyll preservation rate， a value， colour difference value(△E) within 15 d and sensory score as the indicators of consideration， with the resulting composite score as the evaluation index. The results of the one-way experiment showed that the optimum additions of the three colour protectors were A (0.3%)， B (0.075%) and C (0.07%). Response surface method was used to investigate the effect of three colour protectant formulations on the colour of green chilli paste using the composite score as the response value. The results showed that the effects of the three colour protectors on the colour and lustre of green chilli paste were different and ranked as A>C>B. The quadratic polynomial regression equation model of the factors affecting the colour of green chilli sauce was constructed as follows: YComposite Score = +0.85+0.080A+0.030B-0.048C+0.063AB+0.072AC-0.012BC-0.12A2-0.020B2-0.15C2， with a coefficient of determination of R2 of 0.9825， indicating that the experimental data and the model test correlation is good and can be used to determine the optimum colour protection formulation for green chilli paste， i.e. 0.30% addition of disodium hydrogen phosphate， 0.09% addition of zinc gluconate and 0.07% addition of sodium D-isoascorbate. The green chilli paste made with this formulation was bright green and glossy in colour， with an a value of -4.33， an organoleptic score of 94.35 and a composite score of 0.91. The chlorophyll preservation rate of the green chilli paste was 72.62%， which was 30.19% higher than that of the unprotected treatment (only 55.78%)， and the effect of colour preservation was significantly better than that of the traditional process. The colour protection model constructed in this study can accurately reflect the effect of selected colour protectors on the colour quality of green chilli sauce， determine the optimal colour protection process， and solve the problem of chlorophyll browning in green chilli sauce.