In component-oriented cloud service systems, service components share virtual machines (VMs) and their resource utilization ratio is influenced by multiple factors. This paper introduces a method for ensuring virtual machine performance through component migration. The method consists of three phases: migration assembly triggering, target migration component selection, and target virtual machine selection. These phases address challenges related to VM migration and service migration at a large granularity. The approach applies resource dynamic adjustment by analyzing the load characteristics and resource correlation of each component, enabling more precise resource allocation at the component level. This enhances the applicability of resource adjustment and reduces resource costs for cloud service providers while meeting service level agreements (SLAs). The method also considers the reconfigurability and scalability of cloud computing, effectively meeting SLA constraints, and optimizing cloud application performance by adjusting resources at the component level. Experimental verification demonstrates the effectiveness of the proposed method in ensuring virtual machine performance.