Service-Oriented transaction processing is a key technology to ensure the correctness of interaction and collaboration among business processes. For cross-organizational multi-business processes, an approach of modeling and verification of multi-business transactions is proposed in this paper. In the modeling approach, an extended Pi-calculus was proposed to describe business transactions coordination via introducing transaction semantics based on the connection between the process interactions and transaction membrane activities. On the other hand, the model checker is employed for checking whether or not the multi-business transactions satisfy the given properties by equal value transformation of the finite state automaton. Finally, the experimental results have demonstrated that it is an important means of ensuring correctness during the design and implementation of multi-business processes.