With the rapid development of information technology, China has entered into the omnimedia. The omnimedia is information dissemination achieved by the reporter or editor in the media organization; they use radio, television, telecommunication networks, and the Internet through various forms such as images, videos, sounds, and texts, ensure that users can receive media contents without limit of time, area, and form. The advent of the omnimedia era has provided a broad platform and various channels for Chinese netizens to learn current politics and freely discuss social hot issues. Moreover, the omnimedia era brings about the improvement of social transparency, the credibility of the Chinese government will also decline, in addition, there will inevitably be some defects in the management of the Chinese government, which has caused the lack of credibility of the Chinese government. In addition, certain non-positive news involving the government will be exposed through the Internet or in other ways, which will have a certain impact on the governmental image and will seriously damage the governmental credibility. How to improve credibility is a problem that the government urgently needs to cope with and solve. The various reasons for the continuous loss of government credibility were accurately untangled and analyzed in this paper and some suggestions and countermeasures for managing and improving government credibility were given.