Fault handling method and system of air conditioning system

The invention provides a fault handling method and system of an air conditioning system. The method comprises the following steps that after an air conditioning unit is started up, when preset faults appear within a preset fault period timed by a timer, the air conditioning unit sends out fault counting signals to a counter, and the counter receives the fault counting signals and accumulates the appearing frequency of the preset faults; when the appearing frequency of the preset faults accumulated by the counter reaches the first preset fault frequency, corresponding checking and treatment are carried out on the preset faults; and if the preset faults appear still, and the appearing frequency of the preset faults accumulated by the counter at the moment reaches the second preset fault frequency, shutdown protection is carried out on the air conditioning unit, and the air conditioning unit is in the locked state. According to the method, the hidden danger state of the current air conditioning unit can be distinguished in advance, an important protection object can be protected, and the aim of protecting the air conditioning unit better is achieved.