In the sharing context, providing personal data is an important prerequisite for users to have access to service. However, the motivation and the mechanism of the user's privacy disclosure are different from the common online environment because of the change of privacy boundary and interactive relationship. In order to explore the behavior mechanism of users' privacy calculus in the sharing context, this study carries out a questionnaire survey with the sample of share economy's users based on theory of privacy calculus. The data analysis shows that self benefit, altruistic benefit, privacy concern, and users' trust in platform all affect the privacy disclosure intention; Users' perceived benefits are no longer confined to personal interests, but also involve altruistic benefits, which have a positive effect on privacy disclosure intention; Trust on other users can not affect disclosure intention significantly, but trust on platform affect disclosure intention positively.