In order to study the finite?time control of the full?actuated AUV formation, formation control of the full?actuated autonomous underwater vehicles ( AUVs) was investigated. The multi-AUV formation system was modeled as a system with variable communication topologies by predefining the communication ranges among AUVs. Next, the kinematics and dynamics equations were modeled. A finite-time consensus algorithm for second-order system was proposed and the consensus on velocities of AUV ( linear velocity and angular velocity ) and positions ( dis?placement and angles) were carried out. The velocities and positions based on consensus control were substituted into the dynamics equations of every AUV, so the thrust and thrust torque were obtained in three-dimension space. This paper demonstrated the effectiveness of the proposed formation control for multiple AUVs with constraints on variable communication.