The objectives of this study are to analyze the correlation between functional leaves and main grain filling parameters in wheat, and provide references for high-yield breeding of wheat in Shanxi. A total of 51 wheat cultivars from Shanxi Province were used as materials to fit the change regularity of dry weight of grain after flowering using the Logistic equation, and the correlation between main filling parameters and functional leaves was analyzed. The results showed that the main filling parameters were Wt1, Wt2, Wt3, W2, W3, V3, Vm, V2 and Va, correlations between flag leaf inclination and Wt1, Wt2, Wt3, and W2 were significant; the flag leaf area was significantly correlated with Wt1, Wt2, and W2; the second leaf area was significantly correlated with Wt1, Wt2, W2 and Va; significant correlations existed between the spike grain weight/flag leaf area (SGW/FLA) and Wt2, W2 and Va. In high-yield breeding of wheat, we should pay attention to the investigation and selection of flag leaf inclination, flag leaf area, the second leaf area and the spike grain weight/flag leaf area in order to obtain the best filling effect and lay a foundation for high yield breeding of wheat.