To extract total polysaccharides from tussah silkworm excrement, using heat reflux extraction, the effects of solution pH, extraction temperature, extraction time, and solid-liquid ratio on the total polysaccharide yield were investigated. Based on the results of single-factor experiments, the optimal extraction parameters were determined by orthogonal experiments. The in vitro antioxidant capacity of the obtained total polysaccharides was measured by the 1, 1-diphenyl-2-picrylhydrazyl(DPPH) method and 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt(ABTS) method. The optimal extraction conditions were as follows: extraction temperature of 100 ℃, solid-liquid ratio of 1:40, extraction time of 5 h, and solution pH of 9.0. Under these conditions, the total polysaccharide yield was 12.98%. The obtained total polysaccharides from tussah silkworm excrement had good antioxidant activity, and the half-maximal effective concentration(EC₅₀) for DPPH radical scavenging and ABTS radical scavenging were 0.099 8 mg/mL and 0.003 6 mg/mL, respectively. The optimized extraction conditions were stable and reliable, and the total polysaccharides obtained from tussah silkworm excrement exhibited good in vitro antioxidant activity.