【Purpose/significance】 With the popularity and influence of social media, emergency crisis events often trigger a lot of dis⁃

cussion and communication on Weibo and other platforms. In a very short period of time, sudden crisis events may cause irreversible impact on the image and reputation of the event subject. The study of negative public opinion guidance strategies on microblog for emergency crisis events can help public opinion management departments to effectively guide negative public opinions of netizens and improve the response capacity and management level of sudden crisis events.【Method/process】 According to the public opinion char⁃acteristics of emergency crisis event, grey differential equation is established to collect the historical data of emergency crisis event.The prediction model of public opinion law was established by bleaching differential equation to determine the breaking point of emer⁃gency crisis events. The residual test method was used to verify the prediction results of the public opinion law prediction model.【Re⁃sult/conclusion】 The empirical analysis shows that the earlier the information is made public, the easier it is to control the negative public opinion. The higher the accuracy of information, the smaller the scale of negative public opinion dissemination; The higher the information integrity, the smaller the scope of negative public opinion.【Innovation/limitation】 This paper puts forward some strategies to improve the credibility of the government, strengthen the accuracy of information to guide the public's rational judgment, ensure the integrity of information and improve the effectiveness of negative emotion guidance, in order to help the public opinion management de⁃partment better control and resolve negative public opinion. In the follow-up strategy implementation, the public opinion management department should cooperate closely with other relevant departments to timely adjust and optimize the strategy according to the pre⁃dicted results of the law of public opinion.