Now, one of the most important institutions of memory, i.e. social media, has undertaken the structuring of collective memory. They use artificial intelligence and machine learning algorithms to analyze big data. Algorithmic selections of social media with classification, highlighting, deletion and inconsistency in the observability of users' content is like a memory politics that limits narratives to be remembered and forgotten and by creating Memory gaps cause collective forgetfulness and the disintegration of collective memory. The current interdisciplinary research with a qualitative approach in the tradition of cultural studies, using the method of grounded theory and the Strauss coding paradigm, with theoretical and targeted sampling of the text of the interviews, Instagram social media, historical documents related to collective memory, as well Observing related activities and events until reaching the limit of theoretical saturation has been researched in order to investigate the policy of algorithmic memory and its impact on the postmodern discourse of collective memory in Iran. Based on the findings of the research, the central phenomenon is related to all the main categories of power relations, digital knowledge, ideology and global inequality, memory of resistance and the crisis of identity and meaning in the postmodern social situation.