The integration of various networks which adopt different wireless access technology can improve wireless transmission performance and provide mobile users with always best connection. Vertical handoff is the foundation of the integration of the heterogeneous wireless network. In the process of vertical handoff, handoff algorithm is an important part, directly determining handoff performance. Considering the current research hotspot Ad hoc network, multihop is able to expand coverage area of network and reduce single-hop transmission distance. Therefore, a multihop-enabled vertical handoff algorithm TVHOA with multi-attribute is designed in this paper and trust management mechanism when multihop is established to improve the handoff performance of mobile nodes and the network performance after handoff. The simulation result indicates: the algorithm proposed in this paper is superior to traditional SSF (strong-signal first) in the aspect of handoff times, handoff time and throughput