This paper describes the application and performance optimization of Online Judge Systems in terms of web page and database caching, server architecture, testing and processing rules in multi-core environment, front-end asynchronous response, data table design, cross-platform support, source code plagiarism detection, automatic generation of test cases, etc., which enhances the evaluation efficiency while reducing the number of servers, saving operating coses. And then, it discusses the general idea on the implementation of a unified test platform for intelligent optimization algorithms.