Abstract: Internet Ticketing and Reservation System has been an important channel that sold railway tickets. Some applications were using distributed in-memory database to solve the concurrent access pressure, such as ticket-queryservice, order-query-service, passenger-query-service, etc. Because some business logic code needed to be modified frequently, all the service nodes had to be restarted to deploy new program, while this operation usually took a long time. To improve the efficiency of operation and maintenance, based on Java class dynamic loading mechanism, this paper explained the design and implementation of Java class dynamic loading mechanism which was suitable for Internet Ticketing and Reservation System, tested the system module and analyzed the running results of the modules, given a conclusion and some suggestions.