Selenium automated testing tools have been widely used in the field of testing. In the scenario, they need to rely on other compilers or interpreters to perform tests. On the one hand, testers need sophisticated programming skills to use the tools, and on the other hand, test development is too difficult. In order to reduce the automation test threshold, an interpreter based on Selenium is designed for Web automated testing. Firstly, it analyzes the testing principle of Selenium, and builds dependencies on the main test classes based on the usage of the test interface, and then constructs the modules of the interpreter according to the testing requirements of the Web program. For detailed design of each module's syntax, we referred to the programmer's coding conventions, Python, JQuery, and other syntax. Finally, a specific test case is designed to evaluate the interpreter. The experimental results show that the interpreter overcomes the disadvantages of using Selenium's high threshold, makes the written test script more concise and cleaner, and the test performance has also been significantly improved.