Objective: This study primarily investigates the impact of early initiation of intensive lipid-lowering therapy on lipid target achievement rates and the incidence of major adverse cardiovascular events (MACE) in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). Methods: A total of 100 patients with ACS who underwent PCI in our hospital were selected as the study subjects. They were randomly divided into a control group (treated with statin combined with ezetimibe, n = 41), study group 1 (initiated with statin combined with a PCSK9 inhibitor immediately after surgery, n = 32), and study group 2 (received routine oral statin and initiated with a combined PCSK9 inhibitor before discharge, n = 27). The safety of treatment, lipid target achievement, and differences in the incidence of cardiovascular adverse events were compared and analyzed among the three groups. Results: The treatment regimen in study group 1 demonstrated the optimal effect in improving liver and kidney function and lipid indicators, followed by study group 2, while the control group showed relatively weaker efficacy, with statistically significant differences (P < 0.05). The overall incidence of cardiovascular adverse events was 25.00% in the control group, 5.00% in study group 1, and 15.00% in study group 2, with statistically significant differences between the groups (P < 0.05), with study group 1 having the lowest incidence. Conclusion: Early intensive lipid-lowering therapy can significantly improve lipid target achievement rates and reduce the risk of MACE in patients with ACS undergoing PCI, with good safety and significant clinical implications.