The invention discloses a supply-demand-relationship based mobile crowd sensing excitation method and provides a method of interaction between a platform and a smart phone user in a crowd sensing system. Contribution made by each user to the system is considered as resources that are consumed by the user for sensing, and each sensing task has a minimum resource demand. In addition, a supply-demand-relationship based mobile crowd sensing excitation mechanism is provided on the basis, contribution of resources prices and users is decided by the supply-demand relationship. The supply-demand-relationship based mobile crowd sensing excitation method has the characteristics of calculation effectiveness, individual rationality, profitability, cheating prevention performance and non-monopoly property.