Aim To investigate the correlation between plasma miR-1228-5p, miR-34a-5p, miR-192-5p and miR-30a-3p levels and premature coronary artery disease (PCAD) and their early screening value as biomarkers. Methods According to inclusion criteria and exclusion criteria, 6 patients with clearly diagnosed PCAD were included as PCAD group and 6 heathy subjects as control group. Blood was collected from the PCAD group and the control group, and serum samples were extracted and stored. The miRNA levels in the serum of the two groups were detected using DNBseq platform, and the miRNA with significant differences were screened. According to inclusion and exclusion criteria, blood from 78 patients with PCAD, 75 patients with late-onset coronary artery disease and 69 healthy subjects were collected and the selected miRNAs were verified by qPCR. Coronary angiography reports of patients with PCAD were analyzed, and the severity of coronary artery disease was evaluated by Gensini score. Spearman correlation test was used to analyze the correlation between the degree of coronary stenosis and the miRNA. ROC curve was used to analyze the diagnostic value of plasma levels of miR-1228-5p, miR-34a-5p, miR-192-5p and miR-30a-3p for PCAD, and multivariate Logistic regression was used to analyze the influencing factors of PCAD. Results DNBseq platform analysis showed 33 differentially expressed miRNAs, including 17 up-regulated miRNAs and 16 down-regulated miRNAs. The 5 miRNAs with the most significant difference levels were miR-1228-5p, miR-34a-5p, miR-192-5p, miR-424-3p and miR-30a-3p. qPCR results showed that compared with the control group, plasma miR-1228-5p, miR-34a-5p, miR-192-5p and miR-30a-3p levels were increased by 1.7 times, 1.4 times, 0.7 times and 2.5 times in patients with PCAD (P＜0.05). There was no significant difference in miR-424-3p level between the two groups (P＞0.05). Spearman correlation analysis showed that plasma levels of miR-1228-5p and miR-34a-5p were positively correlated with the degree of coronary stenosis in patients with PCAD (r＝0.307, P＝0.004; r＝0.238, P＝0.036). ROC curve analysis showed that the areas under ROC curve for the diagnosis of PCAD by miR-1228-5p, miR-34a-5p, miR-192-5p and miR-30a-3p were 0.3,0.2,0.731 and 0.798, respectively. The area under ROC curve of the combined diagnosis was 0.990, and 95%CI was 0.970～1.000. Conclusions The plasma levels of miR-1228-5p, miR-34a-5p, miR-192-5p and miR-30a-3p in patients with PCAD were significantly increased. The combined detection showed high accuracy in the diagnosis of PCAD, which is expected to be new biomarkers for preliminary screening of PCAD.