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A nonlinear chemical fingerprint method for determining the content of dextrin in milk powder was developed. Firstly, the content of dextrin in milk powder was rapidly determined by using the dynamic nonlinear chemical fingerprint method. Using sulfuric acid, manganese sulfate, acetone and sodium bromate as reaction system, the dextrin with different contents was added into milk powder as milk powder standard samples. The nonlinear chemical fingerprints of milk powder standard samples were obtained, and there was a linear relationship between inductive time or undulatory end time and the content of dextrin in milk powder standard samples, respectively. Then, the content of dextrin in milk powder was calculated by the least square method. The results showed that within 0～30% of mass fraction of dextrin, there was a good linear relationship between the content of dextrin in milk powder and inductive time or undulatory end time, the determination coefficient was 0.9972～0.9991, the recovery was 94.00%～104.89%, the relative standard deviation was 0.17%～1.17%, the determination range of dextrin content in milk powder was 0～30%, and the detection limit of 1.3×10-3～4.7×10-3mg/g was obtained. The developed method was a practical and feasible method for determining the content of dextrin in milk powder, and it had advantages of good accuracy, low cost, simple operation and no sample pretreatment. In addition, the method can be used to determine the dextrin content in different batches of the same brand of milk powder or different brands of milk powder, it can also be used as an approach for the determination of other components in other complex samples.