Micro-service architecture has gradually become the mainstream architecture for building complex business systems, but at the same time, the system architecture has become more complex, and the quality of service assurance becomes a key issue. This study focuses on the quality of service assurance under the micro-service architecture, and solves various problems in the process of service invocation by fusing, degrading and multi-channel invocation. Based on real-time monitoring data of business and equipment, a calculation model of service invocation parameters is proposed, which can refine the calculation of service invocation parameters and support online dynamic parameter adjustment. Through the elegant shutdown and flow preheating method, the quality jitter problem in the process of service restart is solved. The method and model proposed in this study have been fully validated in practical application. The response time and failure rate are greatly reduced, which makes the system run more stably and reliably under the micro-service architecture.