A connection management system for electronic SIM card terminals, a user terminal and an application, and belongs to the technical field of network connections for electronic SIM card terminals. The connection management system comprises a connection management module, a baseband processing module and a connection management server module. The connection management module randomly selects one preset operator Profile X from a plurality of pre-stored preset operator profiles, the baseband processing module establishes a temporary connection channel between the connection management module and a cellular network via Profile X, the connection management module applies for a local Profile A to the connection management server module and downloads the local Profile A from the connection management server module via the temporary connection channel, and the baseband processing module establishes a cellular data connection channel with the cellular network via Profile A. The present invention improves the global cellular data connectivity of terminals.