The rapid advancement of network media technology has given rise to a post-truth era in public opinion ecology, where emotion-driven dynamics and algorithmic recommendations jointly shape new information dissemination trends, posing significant challenges to traditional educational models. As key participants in online public opinion, university students exhibit strong information-seeking tendencies but face heightened risks of post-truth phenomenon spread due to structural deficiencies in new media information discernment capabilities. This study examines the post-truth phenomenon in online public opinion as a focal point, analyzing its formation mechanisms, dissemination characteristics, and profound impacts on ideological and political education in higher education institutions. Five systematic countermeasures are proposed: enhancing fact-tracing mechanisms, facilitating rational emotional expression, reconstructing teacher-student dialogue frameworks, cultivating deep media literacy, and implementing proactive value guidance. These strategies aim to help educators accurately grasp online public opinion patterns, improve the precision and effectiveness of educational guidance, and establish innovative ideological education models adapted to digital era characteristics.