The invention discloses a data returning apparatus of an underwater operation apparatus and a method thereof. The underwater operation apparatus does not interrupt underwater operation, and a beacon data tree can be released during operation. The beacon data tree is floated to a sea surface after being released. When the data tree detects that its own state is out of water, a position informationof the data tree can be determined through a big dipper satellite positioning communication module, the positional information is reported to a shore base and a working mother ship, at the same time,a wireless data-transmission module on the data tree starts, and the positional information is reported to the nearby working mother ship through a wireless mode. The wireless data-transmission moduleand a flash lamp are equipped with the data tree, and are respectively used for wireless communication positioning and stadia positioning, which is convenient for accurate positioning and recovery onthe data tree by the working mother ship in a short distance. Light-transmission devices are arranged on the data tree, the underwater operation apparatus, and a receiving end of the shore base. Thejob data acquisition mode of the underwater operation apparatus can be effectively simplified, a step of first recovery and second disposition is omitted, and work time and economic cost are reduced.