The invention discloses a comprehensive judgment method for a semi-main wiring transformer substation dead zone fault. The method comprises the steps that the three-phase current of each breaker of a whole transformer substation and three-phase voltage on each string are collected in real time; each bus protection, line protection and transformation protection tripping signal in the whole transformer substation is sampled; the three-phase current of the breakers, the three-phase voltage and zero sequence voltage on each string and interphase impedance of the breakers are calculated, a fault area is selected according to the sampled protection tripping signals, and comprehensive fault locating is carried out through the breaker current magnitude and waveform characteristics obtained after protection tripping and the voltage and impedance magnitude. According to the comprehensive judgment method utilizing full substation information of the transformer substation, a breaker unit suffering from the dead zone fault of the transformer substation is selected, high safety is achieved, the acting speed is high, the result can be applied to station domain breaker dead zone protection judgment, the fault clearing time of breaker dead zone protection can be greatly shortened, and the safety of a large power grid electric system is improved.