The invention discloses an inter-group communication method for ships, which comprises a data sending end and a data receiving end, and comprises the following specific steps: firstly, the data sending end and the data receiving end complete handshake; the data sending end automatically detects the communication condition with the data receiving end, and when the data sending end and the data receiving end are in primary communication, the next step is executed; otherwise, skipping to the step 6. According to the invention, when data transmission is carried out for the first time, the data receiving end, the data content to be sent by the data sending end and the sending data sequence are notified through the data notification table; a data receiving end can conveniently establish a tablein time and fill data according to a sequence to finish the transmission of basic data; meanwhile, if the data transmission is not performed for the first time, whether the sequence and format of thedata transmitted this time are the same as those of the data transmitted last time or not can be self-checked, if yes, transmission is continued, and otherwise, a data notification table is reestablished to inform a data receiving end of the specific content of the data transmitted this time.