In order to make rapid respond to the complex and dynamic business needs and operation environment of composite services, a situation aware-adaptive decision-making mechanism is proposed to ensure the smooth implementation of the manufacturing process and provide users with high quality services continuously and steadily. From the individual perspective of intelligent manufacturing cell, a adaptive adjustment system architecture for manufacturing composite service is constructed. According to the changing application scenarios, two adaptive decision-making mechanisms, including situation awareness and subject-situation-action(SSA), are designed respectively. Meanwhile, the decision experiment environment is built by using the muti-agent technology and the association rule method is used to mine decision knowledge. Through the experiment of automobile manufacturing cloud service, the effect of two kinds of mechanisms in different scenes is verified, and the advantages of situation awareness and SSA mechanism are proved from decision accuracy, time and service QoS.