Various types of micro-sensors in smart communication devices can measure a significant amount of potentially useful information. Mobile Crowd Sensing (MCS) between users with smart mobile devices is a new trend of development in Internet of Things. With the powerful sensing capability of smart device and user mobility, various services could be provided by building a trusted chain between service requesters and suppliers. In this paper, we first analyze and summarize the current status of the MCS technology, and a novel credible crowdsourcing service model is proposed based on MCS according to mobility, sociality and complexity of mobile users. Then, some key technologies of model are given in details. Finally, we give the focus of future research work.