1. Discovery and Originality. By observing the local experience in China, I found an interesting phenomenon: rumors in the field of public health still exist for a long time after the rumor is dispelled, the long-term survival rumors has the characteristics of multi-platform survival, survival across time dimensions, survival across spatial dimensions, and content Survival of variants. However, academic circles have done very little research on the long-term survival of rumors after they dissipated; and the linkage effect between platforms has not been paid attention to.

2. Research methods. This article takes 124 rumors that survived for a long time after dispelling the rumors as examples. Rumor cases were published on official rumor refuting platforms such as the "Internet Joint Rumor Refuting Platform" and "State Administration for Market Regulation", as well as commercial rumor refuting platforms such as Tencent's Juzhen Mini Program and WeChat Rumor Refuting Assistant. The screened cases meet the three characteristics of involving public health, being officially refuted, and long-term survival after refuting rumors (whether long-term survival is determined by "Baidu Index", "Baidu Index" is similar to "Google Index"). Useing survival analysis explores the survival time distribution characteristics of the different types of rumors, and the change trend of the survival curve through survival analysis. It is the whole stage of their long-term survival; the cox proportional hazard model is further used to analyze the factors that affect the survival time of rumors.

3. Research results. There are four situations of multi-platform survival rule. According to the life cycle and survival curve of rumors, rumors are divided into four categories. Human observations have found that the four types of rumors have different characteristics. Further related analysis proves that factors such as the communication platform, the magnification of opinion leaders, Types of rumors and textual features of rumors will affect the life cycle and curve of rumors.