With the continuous development of Internet technology, the era of big data has come. The traditional library resource sharing which still at the mode of information island is unable to maximize the use of resources. In order to solve this problem, this study designed a library information resources co-construction and sharing system based on Squid reverse proxy technology. After the system was completed, the login function, user opening function and resource sharing function were tested. Functions of the system were basically normal, but some small details affected users' experience. Therefore, it is necessary to optimize the system code before putting it into use. Moreover in the aspect of resource sharing, the system realized the login of the same user information into different library databases, and users can search same resources in different libraries.