Abstract: For MPLS VPN not suitable for the complex network application with high security requirements because of its lack of providing encryption and certification, only achieving point to point security while being incapable of fine-grained security services, a scheme of enhancing the security of VPN is proposed to ensure the integrity and confidentiality of data. It realizes fine-grained security service strategy based on the security domain and role by integrating VPN and IPSec and using cryptographies such as encrypted authentication, etc.