In allusion to the trust evaluation of partner in Dynamic Virtual Enterprise, a trading practice based trust evaluation model was constructed. The trust evaluation process was divided into real-time feedback information based evaluation, trading history based evaluation and comprehensive evaluation, and the computing methods of every process were put forward. In trading history based evaluation, the relative between the weight of every trading and its trading time was researched. A correction factor of evaluation value was introduced in the process of comprehensive evaluation to reduce the influence of subjective factors in feedback information. Through the research and analysis of simulate experiment, the feasibility and the rationality of this trust evaluation model was verified.