Abstract: The immutable factor of deployed smart contracts needs a strict code review mechanism. For the existing detection tools of smart contract with the defects of inefficient detection for complex paths and rough processing for loop structures, a target-oriented symbol execution path search strategy is proposed. The instrumentation result of static analysis leaded the trace search engine to cover hazardous position quickly to add the detection module. Simultaneously, the loop instruction set and execution variable were extracted to assess the vulnerability in program bounds when loop structure was detected. 114 smart contracts with overflow and reentrancy vulnerabilities selected on the Ethereum blockchain were detected. The experiment results show 14.28% accuracy improvement and 1.61 time efficiency compared with the existing symbolic execution tool.