This paper explores the development status of Marxism on the Internet by collecting Chinese Internet information. A theoretical model of Marxism’s online communication effect in the new media era is constructed by using the fuzzy comprehensive evaluation method, and all kinds of key factors affecting the effect of Marxism mass communication in the new media era are clarified. In response to the empirical research results, specific measures and strategies are proposed in five aspects, namely, communicators, communication content, communication channels, communication audience, and communication environment. The results show that with the development of new media, the penetration rate of Chinese Internet users will exceed 50% by December 2023. The number of Internet media in Chinese government organizations continues to grow, totaling 269,472. The cultivation of Internet Marxism is fragmented, and it is necessary to aggregate and integrate resources in the future. In the guideline layer indicators of Marxist Internet communication effect, the weight of communication content is 0.4187, which is the main factor in the decision-making system, followed by communication audience (0.1845). Downloading and rewarding behaviors in the program layer indicators have a significant impact on the communication effect.