While the coronavirus 2019 (COVID-19) pandemic is spreading all over the world, misinformation, without prudent journalistic judgments of media content online, has begun circulating rapidly and influencing public opinion on social media. This quantitative study intends to advance the previous misinformation research by proposing and examining a theoretical model following an "influence of presumed influence" perspective. Two survey studies were conducted on participants located in the United States (N = 1793) and China (N = 504), respectively, to test the applicability of the influence of presumed influence theory. Results indicated that anger and anxiety significantly predicted perceived influence of misinformation on others; presumed influence on others positively affected public support in corrective and restrictive actions in both U.S. and China. Further, anger toward misinformation led to public willingness to self-correct in the U.S. and China. In contrast, anxiety only took effects in facilitating public support for restrictive actions in the U.S. This study conducted survey research in China and the U.S. to expand the influence of presumed influence (IPI) hypothesis to digital misinformation in both Western and non-Western contexts. This research provides implications for social media companies and policy makers to combat misinformation online.