This paper presents the architecture of composite service execution engine in support with the human task. For the problem of preserving the efficiency of the human task, a method for allocating the human task is proposed. This method uses the established performance evaluation model to reflect the actual performance of the human service resource. Based on this model, the proposed scheduling algorithm can find the human service resource which can implement the human task with better performance. The system implementation and the experimentation verify the effectiveness of the method.