Objectives: Chronic kidney disease (CKD) is an important risk factor for cardiovascular disease, and due to its special pathophysiological mechanism, non-obstructive ACS may not be uncommon in CKD patients. Therefore, the aim of this study was to investigate the relationship between renal function, the occurrence and prognosis of non-obstructive ACS. Methods: CCC-ACS, a hospital-based medical quality improvement project, is a hospital-based medical quality improvement project to improve the compliance of ACS guidelines in China and improve the prognosis of patients. According to the results of coronary angiography, the patients were divided into obstructive ACS group and non-obstructive ACS group (obstructive ACS group was defined as at least one coronary artery stenosis ≥ 50%; the others were non-obstructive ACS group). Outcome was defined as in-hospital all-cause mortality and in-hospital MACEs. Results: A total of 77,586 patients were included, including 2,292 patients (3.0%) with non-obstructive ACS and 75,294 patients (97.0%) with obstructive ACS. In-hospital outcomes showed that although the obstructive ACS group had a worse in-hospital prognosis than the non-obstructive ACS group, and the eGFR<60 ml/min·1.73 m² group had a worse in-hospital prognosis than the eGFR≥60 ml/min·1.73 m² group, further grouping of patients showed that the non-obstructive ACS group with eGFR<60 ml/min·1.73 m² had a worse prognosis than the obstructive ACS group with eGFR≥60 ml/min·1.73 m². Confounding factors adjusted for non-obstructive ACS showed that lower eGFR was associated with a higher risk of in-hospital MACEs. After analyzing the in-hospital medication and discharge medication of patients, it was found that the standardized cardiovascular drug therapy was inadequate in patients with non-obstructive ACS. Conclusions: In patients with non-obstructive ACS, the risk of in-hospital MACEs significantly increased as eGFR decreased. This suggests that we may consider giving standardized cardiovascular drug therapy to patients with non-obstructive ACS.