Abstract: Considering at the trust problem existing in cloud computing environment, a double incentive based on trust and deception detection model CCIDTM (Cloud Computing Incentive and Detection Trust Model) is proposed. The model proposes a set of cloud computing services property evaluation, introducing a dynamic mechanism of trust decaying over time, establishing a double incentive mechanism about service behavior of service providers as well as users evaluate behavior. An algorithm of conspiracy to deceive group testing which improves the model of dynamic adaptation and evaluation of comprehensive is also proposed. Experiment results show that the model results of the assessment service providers closed to the true service behavior. Thus it can effectively resist the attacks of malicious behavior, showing a good robustness compared with the existing trust model.