As the database of municipal administration contains large amounts of sensitive information, we designed this mobile middleware to optimized the exsiting platform and protected the sensitive data be attacted. This middleware is based on MD5 and DES algorithm. MD5 algorithm is used to implement the authentication process.DES algorithm combined with asymmetric encryption and digital signature to ensure the safety of information transmission. The middleware can be integrated in the client device and the Web server of the municipal in the form of dynamic libraries.You can achieve the security goals without need to carry out major changes to the existing resources, greatly reduced the difficulty of deployment.