The next-generation (5G) wireless networks have been evolving into very complex systems due to the diversified service requirements, heterogeneity in applications, devices, and networks. The network operators need to make the best use of the available resources, for example, power, spectrum, infrastructures, as well as data. Large amounts of data, generated from the network and the subscribers, would dramatically help make the system smart and efficient by advanced exploiting. Besides, the synergy of the 5G and the big data would create new services, which promotes a faster digital transformation of the vertical industries. In this paper, we first present the evolution of the big data in the uprising 5G era. Then, an overview of the interplay between the 5G and the big data is provided. Following gives the discussion on challenges and trends of the development of 5G and big data. To further illustrate the benefits, data-driven services are studied.