The invention discloses a gating diode array of a phase-change memory and a preparation method thereof. The preparation method comprises the following steps: carrying out ion implantation on a P-type semiconductor substrate surface, annealing so as to generate heavily doped N-type semiconductor layer; carrying out epitaxial growth on a heavily doped N-type semiconductor layer surface so as to form an intrinsic semiconductor layer; carrying out an etching technology so as to form a first groove used to isolate word lines; depositing in the first groove so as to form a first isolation layer served as isolation between adjacent word lines; carrying out the etching technology so as to form a second groove; depositing in the second groove so as to form a second isolation layer; carrying out the ion implantation in the intrinsic semiconductor layer so as to form a gating diode, wherein the width of the word line is at least more than double the width of the gating diode; forming a word line extraction electrode located above the word lines. Compared to the prior art, by using the gating diode array and the method of the invention, a gating diode driving current can be increased so as to reduce a crosstalk current, and consistency and stability of read-write operation of the memory can be ensured.