File transmission method, instant messaging terminal and system, and computer storage medium

Disclosed are a file transmission method, an instant messaging terminal and system, and a computer storage medium, so as to solve the problem in the case of a bad network environment that excessive human intervention is required during network interruption occurring in file transmission of an instant messaging software, which results in low efficiency and undesirable user experience. The present invention provides a disconnection automatic retransmission configuration option, a disconnection automatic reception configuration option, and a disconnection automatic offline-file-forwarding configuration option for the instant messaging terminal, so that when a file transmission interruption occurs the instant messaging system is capable of automatically retransmitting or resuming the transmission of the file for which transmission has been interrupted, thereby improving the file transmission efficiency.