According to the statistical data of inbound tourism income and inbound tourism reception in Gansu Province during 2006-2017, the characteristics of inbound tourism flow quantity and the evolution of inbound flow quality are presented. The research on the matching degree of the evolution of inbound tourism flow quantity and quality in Gansu Province is conducted and the results show that the overall flow quantity index increases but part of time points and part of periods decreases, that the reason for the declining is the outbreak of the world economic crisis and the insufficient innovation of tourism products of Gansu Province. The quality of tourism flow in Gansu Province as a whole is not good and the index of flow quality tends to decline, the main reason for this is that the inbound tourism development idea pays more attention to scale but neglects the benefits, and that there is short of new type vacation and specific products and projects but sightseeing products are surplus so that industrial consumption chain narrows and the supply and demand of tourism products are mismatched, which result in serious economic problem.