The invention discloses an object volume calculating method based on Kinect. The method comprises the steps of (1), acquiring a depth image and a color image by means of Kinect; (2), calibrating a color camera of the Kinect; (3), setting an ROI area of the depth image, performing image segmentation by means of a foreground color image which comprises a measured object and a background color image of a measurement platform that does not comprise the measured object, and obtaining a binary image of the measured object; (4), converting a background depth image ROI area to a background distance matrix, and performing preprocessing on the background distance matrix, filling in elements which are zero on the background distance matrix, and converting the foreground depth image ROI area to a foreground distance matrix; (5), obtaining a height matrix according to difference between the foreground distance matrix and the background distance matrix; and (6), calculating length, width, height and volume of the object. The object volume calculating method effectively settles problems of high labor intensity and long measurement time in traditional manual measurement, and is a noncontact measurement means. Damage of the measurement object is prevented. A requirement for automatic is satisfied and furthermore measurement precision is improved.