Similar code detection is a common entry point of software refactoring activities. The paper firstly introduces texts mappingbased similar code detection algorithms like the dynamic text mapping algorithm and the suffix tree algorithm. Based on the combination of these two algorithms, a tool for automated similar code detection is implemented. This tool provides not only a capability to detect similar code both between and within the source files, for an improved accuracy, but also an automatic approach to help developers secure similar code candidates, hence improves the efficiency of software refactoring. Finally, the paper analyzes the experimental outputs of practical programs in a financial information system. Its practicality is shown.