In order to study the effect of hydrolase on the gas production performance of mixed anaerobic digestion of residual sludge and kitchen waste leachate, the residual sludge and kitchen waste leachate from urban sewage treatment plants were used as substrates, and the mixing ratio was 1:1 and 2:1, and protease and cellulase were added in the ratio of 1:1, 1:2, and 2:1 (total enzyme addition amount: 60 mg/g TS) to the mixed solution, and mixed anaerobic digestion at a temperature of (38±0.5)℃. The results showed that the gas production performance and disposal effect was the best when protease and cellulase were added in 1:1 in the 2:1 mixed anaerobic digestion system of residual sludge and kitchen waste leachate. Its daily methane production peak is 60.15 mL/g VS, which is 1.84 times higher than that of sludge digestion alone, and 70.49% higher than that of the same substrate without enzymes; the total methane production was 296.17 mL/g VS, which was 75.99% higher than that of sludge digestion alone, and 62.87% higher than that of the same substrate without enzymes; the removal rates of total solid (TS) and volatile solid (VS) were 41.43% and 67.32%, respectively, which were 14.74 and 27.89 percentage point higher than that of sludge digestion alone, and 8.34 and 21.99 percentage point higher than that of the mixed solution without enzymes in the same group, and there was no ammonia inhibition and VFAs accumulation during the digestion process. Using three-dimensional fluorescence spectroscopy combined with parallel factor analysis, it was found that the fluorescent substances present in the mixed anaerobic digestion process were mainly protein-like, fulvic-like, and humic-like. There were significant differences in protein fluorescence intensity in different time periods of digestion. This change was more pronounced in the enzyme-added experimental group. The results of this study can provide a reference for the reduction and recycling of excess sludge and kitchen waste.