Data collection is the first part of measurement of free-form surface, so sampling point planning legitimately is essential, which can improve the efficiency of the measurement.The number of free-form surface sampling points was determined, and the distribution of free-form surface measurement points was discussed. Since the model of center of a figure of homogeneous objects was be able to use in determining the adaptive sampling point distribution, so the sampling algorithm based on the measure of curvature was derived by means of the model of center of a figure of homogeneous objects, and a new method of curvature of the measure was proposed in the algorithm. The results show that this method can describe the curvature of free-form surface better，form adaptive topology mesh of sampling rectangle. The measurement points can be distributed adaptively, in other words, some more points are needed to be measured where the curvature is larger, and less points are needed to be measured in the place where the curvature is smaller. It can provide references for the actual measurement of the known free-form surface of mathematic model.