The invention relates to a multi-functional communication antenna of an underwater vehicle. The multi-functional communication antenna comprises an antenna signal transceiving end, a communication module pressure-resistant cabin cover and a communication module pressure-resistant cabin, wherein the antenna signal transceiving end comprises an antenna cover, a big dipper antenna and a wireless antenna, the big dipper antenna and the wireless antenna are hermetically arranged in the antenna cover, a big dipper communication module, a wireless communication module and a WIFI communication moduleare arranged in the communication module pressure-resistant cabin, a lower end of the antenna cover is hermetically connected with a fixed table arranged on the communication module pressure-resistantcabin cover, and the communication module pressure-resistant cabin cover is hermetically connected with the communication module pressure-resistant cabin. The wireless module, the big dipper module and the WIFI module are integrated, and the multi-functional communication antenna is compact in integral structure, small in size and good in watertight performance and is convenient to assemble and disassemble.