Abstract: Tomato seedlings were used as experimental materials, and the effect of the compound amount of biogas residue on the growth and physiological indexes of tomato seedlings was studied by combining the field test and laboratory test, in order to provide reference for the resource utilization of biogas residue.The results showed that adding proper amount of biogas residue could effectively promote the growth of tomato seedlings.The growth of tomato seedlings in T4 was better, which strength seedling index was 0.30,and its root vigor was 2.12 times that of T3.When the application rate of biogas residue exceeds 50%,the activity of antioxidant enzymes in leaves of tomato seedlings would decrease, the membrane lipid peroxides would increase, and the osmotic regulation ability would be weakened, thereby inhibiting the growth of tomato seedlings.Biogas residues alone were not suitable as substrates for tomato seedlings.Through similarity analysis and comprehensive evaluation of membership function, it could be seen that when the ratio of biogas residue and garden soil was 1∶3（v∶v）,the seedling effect was better, which was better than garden soil seedling and close to peat seedling matrix choose.