In the Autonomous Vehicular Cloud (AVC), when the services requested by the users are comprised of multiple tasks with dependencies in between on the conditions of limited resources of the vehicle, deploying dependency tasks by using Service Function Chain (SFC) can improve the success ratio of task execution. Therefore, this paper studies tasks allocation problem with dependent relationship. Taking into account the stability of the node communication link and its computing capability, we connect the tasks in the order of dependencies into a service sequence accordingly, minimizing the task completion time to deploying the task, thereby to ensure the smooth execution of services and improve the success ration of the task execution. Compared with the Optimal Generation Scheme(OGS)algorithm, the success ratio of this scheme is 11.36% higher in the highway AVC with rapidly changing topology.