This application provides example mobile service upgrade methods, media, and devices. One example method includes receiving a target service invocation request sent by an application, where a target service is one of a plurality of services comprised in a mobile service. A new version of the target service is downloaded from a remote computer in response to determining, based on the target service invocation request, that the target service needs to be upgraded, where the new version is a version that meets a requirement of the target service invocation request. The new version of the target service is loaded and run.