Abstract: To face the problem of vast spent mushroom substrate (SMS) produced from mushroom industries, we analyzed the nutritive compounds of various SMS and studied the bio-efficiency of applying SMS as substitutes for sawdust, cottonseed hull and wheat bran on mushroom cultivation, as well as the effects on organic fertilizer for the yield and quality of Navel orange production. Results showed the possibility of re-utilizing SMS as substrates for Pleurotus cornucopiae, Tricholoma lobayense and Pleurotus abalonus with the bio-efficient for about 64.95%、84.65% and 70.49%, respectively, which were similar as it of CK group obtained. Comparing to CK group, use SMS as organic fertilizer increased the average output of Navel orange for 5.54kg per tree significantly, improved fruit quality and modified garden soil structure. Results indicated that re-utilization of SMS would apply an important role in recycling of natural resources in agricultural production.