An apparatus and method for diagnosing the state of a power cable and measuring the remaining life thereof using VLF TD measurement data, and for determining a replacement time of a power cable using a 3D matrix exhibiting reproducibility of diagnosis of the state of the power cable. The apparatus and method for diagnosing the state of a power cable and measuring the remaining life thereof according to the present invention includes a Weibull modeling unit, a distance limiting unit, a data type classifying unit, a quantity representing unit, a normalization unit, a 3D constructing unit, a risk level calculating unit, and a remaining life measuring unit.