Using mixed sawdust as the main culture substrate of Pleurotus eryngii,the effects of different proportion of wheat bran and corn flour to culture substrate on the characteristics of mycelium and fruiting body,biological conversion,economic efficiency were studied.The results showed that the wheat bran better than corn flour,and the highest yield and economic efficiency was formula D which included 68% of sawdust,30% of the wheat bran,1% gesso,1% sucrose and 0.5% of lime.