Aim at the security issuses in cloud computing

a method based on Combination Weighting Approach of Relative Entropy is proposed to evaluate users behavior trust to analyze the untrust and abnormal behavior effectively

so as to achieve the scientific quantitative evalution for users behavior trust.Combined with the Weighting factor of weighting method which is both subjective and objective

relative entropy is applied to compute the approach degree of weights.Which are set by subjective and objective weighting method

thus the weighting efficient of each weighting menthods weight in conmbination weight can be determined.Finally

fuzzy comprehensive assessment is made for combination weight to get users trust value. Implementation and verification of the model shows that combination weighting method and the model are scientific and operability

and making objective evaluation for the users credit.