As the uncertainty of user requirements in the cloud-edge environment causes the microservice composition logic to be dynamically adjusted with the changes of user needs， a Dynamic Evolution method for Microservice Composition system （DE4MC） in the cloud-edge environment was proposed. Firstly， the user's operation was automatically recognized to implement the corresponding algorithm strategy. Secondly， in the deployment stage， the better node was selected by the system for deployment through the deployment algorithm in the proposed method after the user submitting the business process. Finally， in the dynamic adjustment stage， the dynamic evolution was performed by the system through the dynamic adjustment algorithm in the proposed method after the user adjusting the business process instances. In both algorithms in the proposed method， the migration cost of microservice instances， the data communication cost between microservices and users， and the data flow transmission cost between microservices were comprehensively considered to select better nodes for deployment， which shortened the running time and reduced the evolution cost. In the simulation experiment， in the deployment stage， the deployment algorithm in the proposed method has average running time of all scales 9.7% lower and total evolution cost 16.8% lower than those of the combination algorithm of Heuristic Algorithm （HA） with Non-dominated Sorting Genetic Algorithm-Ⅱ （NSGA-Ⅱ）； in the dynamic adjustment stage， compared with the combination algorithm of HA and NSGA-Ⅱ， the dynamic adjustment algorithm in the proposed method has the average running time of all scales 6.3% lower， and the total evolution cost 21.7% lower. Experimental results show that the proposed method ensures timely evolution of the microservice composition system in the cloud-edge environment with low evolution cost and short business process time， and provides users with satisfactory quality of service.