The invention discloses a heat recovery multi-split air-conditioning system communication connection error detection method. The heat recovery multi-split air-conditioning system communication connection error detection method comprises the steps of 1, judging whether communication connection between an air conditioning unit and a pipeline control module is wrong or not by detecting whether the pipe temperatures of each indoor unit when the air conditioning unit operates is abnormal or not, and marking the indoor unit with wrong communication connection; and 2, switching the control mode of the indoor unit, and finding the indoor unit with the pipe temperature varying with the control mode correspondingly from all the other indoor units, wherein the found indoor unit is the indoor unit which is actually controlled through the pipeline control module remaining communication connection with the marked indoor unit. By means of the detection method, the communication connection error can be detected in time. The invention further discloses a heat recovery multi-split air-conditioning system.