：谣言是一种待证实的信息。对不同真实度的网络谣言与正面信息的交互规律进行研究，可为高效辟谣提供科学依据，以节约辟谣成本。分析公共危机事件下的网络谣言发生机制，提出谣言真实度参数改进谣言传播公式，以百度新闻帖子数量的变化为依据，构建网络谣言传播规律的宏观模型，并进行仿真与实证分析。由实证结果可知，真实度高的谣言传播范围更广，需要更有说服力、更具有情绪引导力的正面信息才可以有效遏制。因此，应当针对谣言的真实度进行分级管理，以达到节约行政成本、精准辟谣的效果。

Rumor is a kind of information to be confirmed. Before the rumor is falsified, the research on the interaction and confrontation between online rumor with different authenticity grade and the positive information can provide scientific basis for efficient and low-cost rumor refutation. Analyze the mechanism of the occurrence of online rumors in public crisis, improve the rumor spreading formula by proposing the rumor authenticity parameter, build a macro model of online rumor spreading based on the change of the number of news posts of Baidu, and carry out simulation analysis and empirical test. The results show that rumors with high authenticity grade spread wider and need positive information with more persuasive and emotional guidance to contain. Therefore, rumors should be refuted hierarchically according to their authenticity grade so as to save administrative costs and scotch them accurately.