In order to satisfy customers' experience needs with strong interactivity, fast response speed of Web applications, this paper designs and implements a data operation method based on UI components using Ajax technology, and offers a solution of Web application system based on lightweight data operation architecture. It separates interface design, business logic processing and data access to increase the independence of program design, and introduces Ajax asynchronous communication mode to reduce the load of servers and improve time response of data interaction. Using hierarchical design data interface, operation is clear, concise and convenient. In the practical application, the architecture is easily combined with existing mainstream Web UI and has some certain commonality. Finally using ExtJs and ASP.NET, application examples of petrochemical corrosion evaluation system was designed and implemented.