To solve the problems associated with the application of multilevel security to actual networks, such as flexibility, availability, security, and secure communication, this study proposes a multilevel security network communication model based on multidimensional control. In the model, access control is retained on the basis of security labels. In addition, relational restraints among protection domains, credibility degree restraints of subjects on security attributes, aggregation inference control restraints, and secure tunnel control restraints are introduced and applied. Thus, secure information exchange within a multilevel security network information system is ensured. Moreover, using this model, multilevel security virtual networks with logical and independent characteristics can be built to accomplish secure interconnection and communication between nonequivalent members, thereby reducing the probability of information leakage. Finally, the security of the model is confirmed by applying the nontransitive, noninterference theory, and the typical application of the model in actual networks is described.