How to effectively locate resources is a very important factor affecting the performance of Grid environment.The authors propose a novel method which utilizes trust relations existed implicitly among network nodes to construct a secure and available resource trust network(SARTN),meanwhile provide the theory and method of SARTN.Combining passively discovery with actively discovery,applying Small World theory,optimized time complexity is achieved, and the performance of Grid resource discovery is promoted.Through analysis,the proposed solution is scalable,secure and efficient in Grid.