Objective:To explore the relationship between cardiac discomfort symptoms, fear of disease progress and post-traumatic stress disorder (PTSD) in patients with acute myocardial infarction(AMI) after discharge, and to clarify main intervention direction of PTSD in patients with AMI.Methods:Patients with AMI who were discharged from Tangshan Gongren Hospital between 1 month and 1 year were selected from November 2019 to November 2020.The cardiac discomfort symptoms scale, fear of progress questionnaire(FoP-Q-SF) and post-traumatic stress disorder self-rating scale(PTSD-SS) were used to investigate cardiac discomfort symptoms, fear of disease progress level and post-traumatic stress disorder status.Spearman rank correlation analysis was used to analyze the relationship between cardiac discomfort symptoms, fear of disease progress and post-traumatic stress disorder by SPSS 24.0 software. The mediating effect of fear of disease progress was analyzed by AMOS 24.0 software.Results:The PTSD score was (32.78±12.38) of patients with AMI discharged from hospital for 1 month to 1 year and the incidence of PTSD was 12.3%.Spearman correlation test showed cardiac discomfort symptoms and fear of disease progress were positively correlated with PTSD( r=0.530, 0.723, both P<0.01) and cardiac discomfort symptoms was positively correlated with fear of disease progress( r=0.518, P<0.01). Mediating effect test showed that fear of disease progress was a complete mediator between cardiac discomfort symptoms and PTSD. Conclusion:Cardiac discomfort symptoms can affect PTSD through a complete mediator of fear of disease progress.