The invention relates to the technical field of automation and control, and discloses a method and a system for material measurement, and solves problems in the prior art that when a belt conveys materials, foreign matters which endanger operation safety of the belt cannot be found in time accurately. The method comprises: obtaining first section line data of materials on a belt; according to the first section line data, calculating to obtain ratio of sectional area of the corresponding material and average curvature, the average curvature being average curvature of a curve corresponding to the first section line data; according to the ratio and a comparison result in a preset ratio range, providing a prompt message that whether the material has an abnormal shaped object, the preset ratio range being the ratio range of the corresponding section area and the average curvature when the material does not have an abnormal object. The method and the system are suitable for measurement of belt conveyed objects.