The invention provides a system for accelerated water-treeing of a 10 kV crosslinked polyethylene cable sample. The system comprises an epoxy resin box body, a DC high-voltage source, mechanical arms, a grounding copper sheet and a heating plate, wherein a sealing hole allowing a cable to pass is formed in each of two opposite side edges of the epoxy resin box body; the two ends of the cable are exposed from the sealing holes which are sealed by two sealing rings; an insulating layer and a semi-conducting layer of one of the ends exposed out of the corresponding sealing holes are peeled off to expose a copper core; the DC high-voltage source is used for being connected with the copper core; a salt solution is injected into the epoxy resin box body to immerse the cable; one end of the grounding copper sheet is immersed into the salt solution, and the other end of the grounding copper sheet is grounded; the part, immersed into the salt solution, of the cable is needle-pierced to form a plurality of small holes; the heating plate is connected with the epoxy resin box body; the two mechanical arms are respectively arranged on the outer sides of the two sealing holes. The system can simulate the water-treeing, thermal and mechanical aging of crosslinked polyethylene cables in humid and over-heated environments, and meanwhile, well keeps the integrity of the cables.