The government information release of a serious emergency is an important part of dealing with emergencies and making government affairs public.Timely and effective information release enables the public to get the warning and development information of emergencies in time，and take preventive measures as soon as possible.It is very important to reduce the harmful consequences of the emergency，alleviate the panic，enhance the credibility and implementation of the government，and maintain social stability.In this paper，the importance of government information release in dealing with serious emergencies is summarized.Taking the example of the 7.21 rainstorm in 2012 and the 7.16 rainstorm in 2018，the public opinion characteristics of serious natural disaster emergency is analyzed.Based on the development of mobile Internet and the relevant laws and regulations of the state，the requirements of information release and public opinion response when major emergencies occur in Beijing as the capital of the country is studied.Five difficult points is analyzed，which including diversity of channels，widely of population coverage，timeliness，accuracy and acceptability.At the end，the countermeasures and suggestions are put forward.