The invention discloses a power cable defect detection method based on a cloud platform. The power cable defect detection method comprises the following steps: performing axial vertical irradiation ona to-be-detected power cable by utilizing X rays; Receiving X-rays penetrating through the power cable to be detected to generate a detection image in real time; Collecting a detection image generated in real time and sending the detection image to the cloud platform; Preprocessing the acquired detection image; And identifying the defects of the preprocessed detection image, giving an identification result, judging the defect hazard of the preprocessed detection image, and giving an evaluation result. The invention further discloses a power cable defect detection system based on the cloud platform. The power cable defect detection system comprises an X-ray generation module, an image generation module, an image acquisition module, an image preprocessing module and an image defect recognition module. The defect detection result of the power cable is stored in the cloud platform, so that detection personnel can download the defect detection result through the intelligent mobile terminal, and the working efficiency is improved.