Abstract: One-year-old seedlings of Triadica sebifera were investigated in this study with six biochar addition treatments established, namely 2% rice husk biochar (by mass ratio, the same below), 4% rice husk biochar, 6% rice husk c biochar, 2% bamboo biochar, 4% bamboo biochar, and 6% bamboo biochar, along with a control group (0%). The contents of soluble sugar, soluble protein and proline in the seedlings were measured on the 30th, 60th, 90th and 120th days after application, and the relevant physiological indices were analyzed by using one-way analysis of variance (ANOVA). The results indicated that the contents of soluble protein, soluble sugar and proline in the T. sebifera seedlings in all six biochar treatments were higher than those in the control group throughout the experimental period. Compared with the control, Z4 (4% bamboo biochar) and D4 (4% rice husk biochar) demonstrated superior performance with the soluble protein content increasing by 13.65% and 16.97%, the soluble sugar content by 43.60% and 28.11%, and the proline content by 24.50% and 18.52%, respectively. Based on the three physiological indices (soluble sugar, soluble protein, and proline contents), the membership function method was employed to score and rank the effectiveness of different treatments. The comprehensive evaluation value of the Z4 (4% bamboo biochar) treatment was superior to those of the other treatments, indicating the addition of 4% bamboo biochar to soil is more effective in promoting the growth of T. sebifera seedlings.