Background: To evaluate the impact of global budget payment (GBP) reform on the quality of healthcare among inpatients with heart failure (HF) and analyze the influencing factors of healthcare quality in the context of GBP reform. Methods: The administrative data on patients with HF from January 1, 2014 to December 31, 2017 were used, and the in-hospital mortality and length of stay (LOS) were compared using logistic regression and zero-truncated negative binomial regression, respectively. The content analysis method was then used to organize and analyze the records of in-depth interviews with key insiders. Results: A total of 4222 eligible HF patients and 58 interview records were finally analyzed. The in-hospital mortality increased from 1.21% to 3.58% after the GBP reform was implemented (OR, 2.197; 95% CI, 1.153 to 4.229). The average LOS in the pre-budget and post-budget groups was 9.65 days and 9.07 days (IRR, 1.012; 95% CI, 0.997 to 1.027), respectively. Additionally, the top three influencing factors ranked by key frequency analysis are the diagnosis and treatment technology level (50, 86.21%), the supervision of healthcare quality (50, 86.21%) and the implementation of the core system in healthcare quality system (49, 84.48%).Conclusions: The implementation of the GBP had a detrimental effect on the outcome quality for inpatients with HF. Besides, hospital administration, especially quality control, was the most important factor affecting healthcare quality after the implementation of the GBP reform. GBP policy possibly needs to be further improved by policy-makers.