The invention discloses a leak alarm device of a refrigerator of an air conditioner, and relates to an anti-leak technology of the refrigerator of the air conditioner. The leak alarm device of the refrigerator of the air conditioner comprises an air conditioner pipeline, a pressure detector and an alarm, wherein the air conditioner pipeline comprises an inner layer of a pipe and an outer layer of a pipeline, an interlayer cavity is formed between the two layers of the pipes, and the pressure in the interlayer cavity is greater than that of outside of the outer layer of the pipe and is smaller than the pressure in the inner layer of the pipe; the pressure detector is connected to the interlayer cavity and is used for detecting the pressure change of the interlayer cavity; when the pressure of the interlayer cavity is increased to an upper limit of a predetermined pressure interval, an alarm signal 1 that represents large pressure is output, when the pressure of the interlayer cavity is reduced to a lower limit of the predetermined pressure interval, an alarm signal 2 that represents small pressure is output. The refrigerator is circulated in the inner layer of the pipe and the inner layer of the pipe is covered with the outer layer of the pipe so as to prevent leakage of the refrigerator of the air conditioner due to rupture of the inner layer of the pipe; the pressure between the outer layer of the pipe and the inner layer of the pipe is detected to judge whether the refrigerator of the air conditioner has leak, and the corresponding alarm is output.