Abstract: Provided are a method and device for transmitting a service message. The method for transmitting a service message includes that: a copy of processed service message is cached; a format of the processed service message is converted and the format-converted processed service message is then transmitted to a corresponding service gateway; and retransmission processing is performed, upon a failure in transmitting the format-converted processed service message, based on the processed service message cached. The method caches a service message before transmitting the service message, and upon a failure in transmitting the service message, retransmits the cached service message, thus improving the success rate of service message transmission, and reducing service loss.