In the era of mobile Internet, some online media, in pursuit of click-through rate and page views, deliberately create the third truth between truth and falsehood by means of communication based on facts and deviating from facts, thus catering to the emotions of the audience in the "post-real era" and leading to the paradox between digital technology and media ethics-the click-through rate is increasing, the influence is expanding, the professional quality of communicators is deteriorating, and the values of the audience are distorted. In this regard, online media should not only adhere to the authenticity orientation of professional ethics, but also constantly adjust the cognitive mode and practical path of media ethics, and change media ethics from peripheral to internal, so as to improve the media literacy of social platform participants and prevent the spread of the antinomy between communication efficiency and media ethics.