Abstract: Using spent substrate after pleurotus eryngii cultivation with Jucao as the experimental materials and adopting orthogonal design, the effects of the extraction temperature, extraction time, solid/liquid ratio and extraction times on extraction rate of crude polysaccharide from spent substrate after Pleurotus eryngii cultivation with Jucao were studied. And taking the yield of polysaccharide as evaluating indicator to optimize extraction process. The results showed that the optimum extraction processes were extraction temperature 90℃, extraction time 2h, ratio of material to liquid 1:20 and extracted 3 times, and under this condition the yield of crude polysaccharide from spent substrate was 3.62%.