According to the question of cloud drop weight in the existing trust model based on cloud model

a new trust evaluation model based on trust cloud is proposed.Credibility of evaluation data is estimated according to evaluation number and evaluation consistency of the feedback entity;History evaluation data is regard as the quantitative universe of discourse;Trust cloud of entities property is based on the weighted backward generation cloud algorithm;uncertainty factor of the evaluated entity and laterality factor of the buyer entity are introduced for trust decision-making at last.Simulation and analysis show that the model proposed in the paper can reflect a sellers property more accurately and can provide a favorable reference for a buyer entity in e-commerce.