Exploring the impact of the number of multiple resource additions on the leaf morphological characteristics and biomass of dominant plants in desert steppe is of great significance for revealing the response characteristics and adaptation laws of desert steppe vegetation to global change. In order to analyze whether different number of resource addition will affect plant functional traits and aboveground biomass,gradients of resource addition number were set (0 (control (Cont,natural precipitation)); 1 (nitrogen (N) addition,phosphorus (P) addition,potassium (K) addition,+ 50% precipitation); 2 (PK addition,NP addition,NK addition,N+50% precipitation); 3 (NPK addition); 4 (NPK+50% precipitation)) to study the impact of the number of multiple resource addition on the leaf traits and biomass of the dominant plants Allium polyrhizum and Stipa glareosa in the desert steppe,providing a theoretical basis for desert steppe plants to respond to multiple global change factors. The research results are as follows: (1) There are significant differences in the responses of leaf dry matter content (LDMC) and leaf nitrogen content (LNC) of Allium polyrhizum and Stipa glareosa to the number of multiple resource addition: with the increase in the number of multiple resource addition,the LDMC of Allium polyrhizum and Stipa glareosa decreased significantly (P<0.05),but plant height and specific leaf area (SLA) did not change significantly (P>0.05). In addition,the fresh leaf weight and leaf nitrogen content of Allium polyrhizum increased significantly with the increase in the number of multiple resource addition (P<0.05). The fresh leaf weight,plant height and specific leaf area reached the highest when four resource elements were added,while LDMC was the lowest. (2) The number of multiple resource addition had no significant impact on the aboveground biomass of the two dominant plants (P>0.05). (3) The aboveground biomass of the two dominant species was significantly positively correlated with plant height and plant density (P<0.05); and had no correlation with SLA,LDMC and LNC (P>0.05). (4) The structural equation model showed that the number of multiple resource addition indirectly increased the aboveground biomass by increasing the plant density,specific leaf area and leaf nitrogen content of Allium polyrhizum and Stipa glareosa. In conclusion,compared with single resource addition,multiple resource addition will have a complex impact on the functional traits and biomass of dominant plants in the desert steppe; under the background of multiple resource changes,functional traits serve as effective indicators for predicting aboveground biomass. This research is essential for managing desert steppe vegetation in the context of ongoing global change.