[Purpose/significance] The government public information service is not only an important part to meet the social information demand and support the national strategy, but also an inevitable requirement to deal with the event control, public opinion guidance and stabilize the people's mind rapidly and effectively in the crisis situation. Reveal? ing the formation mechanism of government public information service accessibility under crisis situation and exploring the path of improving service accessibility will help to improve the efficiency of government crisis response and dispos? al. [Method/process] Based on the research paradigm of“Problem- oriented- mechanism analysis- implementation path”, this paper focuses on the realistic predicament of the government public information service in major public health emergencies, and adopts the grounded theory analysis method, take the three information service platforms of “Weijia Garden”,“iShenzhen”and“With bid”, which effectively exert the service efficiency during the crisis as exam? ples, this paper analyzes the key factors and the forming process of public information service from the perspectives of supply side and demand side, and expounds the path of service promotion on the basis of constructing the mechanism model. [Result/conclusion] The results show that:（1）under the crisis situation, the demand pressure and the crisis pressure are the important driving forces to promote the government's public information service access.（2）The govern? ment public information service has experienced the process of“Pre-crisis warning learning, inter-crisis coping learn? ing and post-crisis iterative learning”. The effective supply at the supply end and the accurate identification and feed? back at the demand end contribute to the realization of supply-demand coupling. The resilience remolding of service or? ganization is the key factor for service system to break the oppressive interference and deal with the dynamic situation, and it needs the help of the effective embedding of digital information platform.（3）the service path of“Digital intelli? gence drive-organization coordination-idea leap”proposed in this paper can be promoted, which is beneficial to im? prove the quality and efficiency of government public information service in the new stage of“Wisdom Governance”, and realize the matching of supply and demand, strengthen the government's function under the crisis situation.