Sharing economy is associated with a series of economic activities in terms of renting, lending, trading, bartering and swapping of goods, service, space or money, that take place in organized systems or digital platforms. In this research, we interviewed 50 drivers, a kind of users type who provides cars and service from a car-sharing digital platform. Based on the prior studies of motivation, we combined Social Exchange Theory (SET) and Technology Acceptance Model (TAM) to identify salient motivators in this context. Furthermore, building on Self-determination Theory (SDT), we propose a motivation model of users’ sharing option in digital platform. The findings extend literatures of motivation researches in the context of sharing economy as well as help guide the development and operation of sharing economy digital platform.