This paper aims at identifying challenges in the application of 5G technology and analyze the challenges based on experts' opinions. We recognize the barriers and challenges of application of 5G technology by reviewing literature and interviewing experts. We analyze the identified challenges using the interpretive structural modeling (ISM) and cross-impact matrix multiplication applied to classification analysis (MICMAC), determining the relationship between the challenges, finding out how they interact with each other, and finally uncovering the root causes that trigger other challenges. Suggestions are given to promote the application of 5G technology, including 1) study deeply into related technologies of 5G communication network, 2) devoted to the development of 5G technology-related talents in various industries and enhance enterprises' understanding of 5G technology, 3) refine the laws, supporting standards and regulations for the application and 4) arrange more base stations. Practitioners can infer what challenges should be firstly taken into consideration and then decide on what measures should be taken to reduce the negative impact in the process of promoting 5G application.