The purpose of this experiment was to study the intrinsic differences between the physicochemical properties of soybean meal and the alternative soybean meal protein combinations, to determine the relationship with feed pelleting characteristics and pellet quality, and to evaluate the pelleting characteristics of alternative soybean meal protein combinations. In this experiment, seven unconventional protein sources, including Clostridium autoethanogenum protein, cottonseed protein concentrate, corn gluten meal, peanut meal, cottonseed meal, rapeseed meal, and distiller’s dried grains with solubles, were selected to prepare six groups of protein combinations for pelleting and processing experiments. The physicochemical properties of the mash feed, the pelleting characteristics and the quality of pellet feed were determined, the correlation between physicochemical properties and pelleting characteristics was established by partial least squares regression analysis, and the pelleting characteristics of different protein sources were evaluated by entropy weight TOPSIS analysis. The results showed that: 1) there were some differences in the physicochemical properties, pelleting characteristics and pellet quality in different groups. Among them, the water absorption, water solubility and swelling degree of the SBM group were significantly higher than those of the other groups (P<0.05), but the power consumption per ton and the pelleting rate were also significantly higher than those of the other groups (P<0.05). The compression degree and angle of repose of the C4 group were significantly higher than those of the other groups (P<0.05). The protein dispersion index of the C2 group was significantly higher than that of other groups (P<0.05). The pellet durability index of C5 group was significantly higher than that of other groups (P<0.05). The hardness of C1 group was significantly higher than that of other groups (P<0.05). 2) The physicochemical properties had a significant effect on pelleting characteristics and pellet quality . The compression degree was negatively correlated with pelleting rate, and positively correlated with pellet durability index and hardness., The water absorption index and swelling degree were positively correlated with the power consumption per ton and the pellet durability index. The viscosity characteristic values were positively correlated with the power consumption per ton. The denaturation time and denaturation temperature were negatively correlated with the power consumption per ton. 3) Entropy weight TOPSIS analysis showed that the the pelleting characteristics were ranked from best to worst: C5 group, C6 group, C2 group, C1 group, C4 group, C3 group, and SBM group, and the pellet quality of each group was ranked from best to worst: C1 group, C4 group, SBM group, C3 group, C5 group, C2 group, and C6 group. The results of the study provide basic data and reference for the selection and processing application of new and unconventional protein sources.