A method for detecting a clogged state of a pipe of a heat pump type multi-air conditioner includes: detecting a temperature of a pipe of an arbitrary indoor heat exchanger among a plurality of indoor heat exchangers; detecting a pressure of a refrigerant sucked into an arbitrary outdoor unit among a plurality of outdoor units in case of performing an air-conditioning operation, and detecting a pressure of a refrigerant introduced into the arbitrary indoor heat exchanger after being discharged from an arbitrary outdoor unit among the plurality of outdoor units in case of performing a heating operation; and comparing a pressure corresponding to the detected temperature of the pipe and the detected pressure of the refrigerant and determining whether the pipe is clogged based on the comparison result. By detecting a clogged state of a pipe, the heat pump type multi-air conditioner is prevented from being damaged due to a clogged state of the pipe.