Provided is a submersible floating aerator, including a submersible hollow shaft motor (1) including a hollow shaft (2), a bottom shaft extension (4), a first motor flange (15), a second motor flange (16), a first flange (24) and a second flange (25), a gas-ring compressor (17), a base (21) having a gas inlet hole (22), a gas inlet tube (23), a dome (26), a propeller assembly (60) and an air outlet opening (18); wherein the base (21) is fixed on the top of the gas inlet tube (23), the gas-ring compressor (17) is fixed on the base (21) via a bracket (19); the air outlet opening (18) is connected to the gas-inlet hole (22) via a pipe (20); the gas inlet tube (23) is fixed to the first motor flange (15) via a first flange (24); the second motor flange (16) is fixed to the dome (26) via the second flange (25); the bottom shaft extension (4) is coaxially connected to the propeller assembly (60); and the hollow shaft (2) rotates along with the propeller assembly (60). The submersible floating aerator features large aeration depth, high utilization of oxygen, and uniform gas distribution.