The invention belongs to the field of the nondestructive testing application technology of nuclear power station equipment and in particular relates to a viewing-angle-correction-based video measurement method. The viewing-angle-correction-based video measurement method comprises the following steps: acquiring an image by a vidicon in real time and adjusting the vidicon to acquire a video finally; emitting four parallel laser beam groups by four lasers and using the distance as the video measurement calibration; carrying out screenshot when a defect exists in the video, outlining a laser spot and reading the pixel information of the laser spot; separating a red information channel from a green information channel and performing threshold segmentation on the channels respectively to obtain a binaryzation image, performing elliptical fitting and extracting the core of the laser spot; correcting the viewing angle of the vidicon, outlining a defect area of the image and performing defect edge extraction; and enabling the defects to form a simply-connected outer rectangular envelope, calculating the physical dimension of the outer rectangular envelope and finishing the measurement. The method has the beneficial effects that the method can meet the requirements for video checking and surface display checking of the nuclear power station equipment, and the checking efficiency and the measurement precision are improved.