The optimum precursor peptides were prepared for Maillard reaction by using enzymatic hydrolysis of wheat gluten proteins. Setting the degree of hydrolysis (DH) and protein dissolution rate as main indexes, the optimum parameters of enzymatic hydrolysis were optimized by partial least squares regression as follows: the concentration of complex protease Ⅰ (2 000 U/g), hydrolyzing with complex protease Ⅰ for 3 h, aminopeptidase concentration (400 U/g), hydrolyzing with aminopeptidase for 2 h, and water/substance ratio (1:12 g/g). The main components of the hydrolysates were small molecule peptides under the above hydrolysis conditions, and the proportion of free amino acids in the enzymatic hydrolysate was 5.59%. The proportion of peptide-bound amino acids in the enzymatic hydrolysate was 94.41%, and the proportion of components with the relative molecular weight smaller than 1 000 was 92.83%. Moreover, the obtained gluten peptides were used to prepare wheat gluten peptides-xylose (WGP-xyl) Maillard reaction intermediates (MRI). Through a two-stage temperature rising process, the optimum preparation conditions of WGP-xyl MRI were determined as follows: the ratio of xylose and peptides was 10%, the pH of the mixture was adjusted to 7.5 and heated at 70 ℃ for 120 min.