Method, device and system for transmitting paging message

The invention discloses a method, a device and a system for transmitting a paging message. The method includes that a transmission site determines the paging message length of the passing message according to lengths of paging indication messages to be borne by the paging message; the transmission site sets a value of a length domain of the paging message according to the paging message length and a length indication granularity indication message or the predefined length indication granularity; and the transmission site transmits the paging message to a receiving site. According to the length indication granularity indication message or the predefined length indication granularity, the lengths of the paging indication messages borne by the paging message are mapped with the length of the paging message one by one, and the lengths of the paging indication messages borne by the paging message are determined, so that the paging message can bear a lot of paging indication messages, and requirements for the large user quantity can be met.