In order to improve efficiency, reduce unsafe cash flow and provide the basic data for Project Cost Accounting System, a web-based Network Financial Reimbursement System was designed to replace the traditional paper-based system. Analyzing the traditional reimbursement processes and finding the balance of efficiency, security, accuracy and convenient, the author studied automatic processing of accounting documents, analyzed data structure of NC Financial Management System and designed the interface for NC System and Network Reimbursement System, which greatly reduced the workload of the finance staff. Running results showed that the classification of reimbursement information and database collection of NC database can realized corresponding automatically. In addition, Serverlet interface technology solved the security issues of Online Reimbursement System and NC System. However, this system still need to be improved and legally valid signature for electronic process and other issues should be studied in the future.