With the development of information technology, the news media industry has entered the all-media era. Today, everyone is a communicator, and the audience has more diversified channels to obtain news information, but it also leads to the truly useful news being easily overwhelmed. In order to analyze the strategy of news dissemination in the all-media era, this paper analyzes different types of news media platforms and audiences based on big data mining technology. The mining results show that cultural news has the largest share on radio, TV, and video sites, with 27.5% and 57.3%, respectively. Social news had the largest share on news sites, at 29.8%. Political news has the largest share of mobile clients at 27.9%. Economic news has the largest share on social media platforms, with 23.5%. In addition, the news is viewed much more on new media, such as video websites and social platforms, than on traditional media, such as newspapers, magazines, TV and radio. In terms of the exposure rates of different types of news audiences to media platforms, the average exposure rates of newspapers and magazines, TV and radio, news sites, mobile clients, social platforms and video sites are 8.83%, 28.30%, 44.49%, 59.57%, 71.03% and 90.46%, respectively. In the era of full media, news dissemination should focus on applying new communication technologies, enriching the presentation form of news, and selecting reasonable topics for the characteristics of audiences on different platforms. The analysis of news communication strategy based on big data mining can grasp the pain points in current news communication, which is of great guidance for transforming news communication in the era of full media.