Considering that decision maker may hesitate to give the assessed value in the scenario of time urgency and incomplete information, the emergency group decision making method of internet public opinion outbreak based on hesitant fuzzy set is proposed. Firstly, the weight determination model of each evaluation index is established by hesitant fuzzy information entropy and cross entropy. Secondly, the HFWA and score function are used to calculate the evaluation score of each evaluation index. Then, using the weight value and evaluation score of each index to calculate comprehensive harmfulness score of internet public opinion emergency to assist emergency departments to determine the disposal order. Finally, the effectiveness of the proposed method is proved by a case study.