The invention belongs to the technical field of cable preparation, and particularly relates to a
copper core and aluminum core plastic insulation
power cable and a preparation method thereof.The preparation method comprises the following steps that modified
magnesium hydroxide and
modified carbon black are dispersed in absolute ethyl
alcohol, an
acetic acid solution is added for stirring reaction, and composite particles are obtained after filtering and
drying; the modified
magnesium hydroxide is obtained by treating
magnesium hydroxide with
triethyl borate and KH-560; the
modified carbon black is obtained by treating
carbon black with TEOS, APTS and
phosphorous acid; and uniformly mixing EVA, the composite particles, PE-g-MAH, an
antioxidant and a
lubricant, feeding the mixture into an extruder, and performing concentric
extrusion with the cable core to obtain an outer sheath, thereby obtaining the
power cable. According to the invention, the outer sheath containing the composite particles is coated outside the cable core, so that the service life of the cable in an
ultraviolet environment is prolonged, and the
smoke density of the cable in a fire disaster condition is reduced at the same time.