The invention relates to a distribution transformer full-life-cycle cost system comprising a first obtaining module used for obtaining constant value parameters of a plurality of different types of power distribution transformers; a first calculation module used for calculating a first cost value of the corresponding distribution transformer through the constant value parameter; a second acquisition module used for acquiring time-varying parameters of a plurality of different types of distribution transformers; a second calculation module used for calculating a second cost value of the corresponding distribution transformer according to the constant value parameter and the time-varying parameter; a third calculation module used for calculating a corresponding full-life-cycle cost value ofthe distribution transformer; and a sending module used for sending the life cycle cost values of the plurality of distribution transformers to the analysis module. According to the constant-value parameters and the time-varying parameters, the corresponding full-life-cycle cost values of the distribution transformer are accurately calculated, and the analysis module performs comparative analysison the multiple cost values so as to accurately perform economic benefit comparison on the distribution transformer.