Curve-face gear pair is a new type of face gear pair with variable transmission ratio. Concerning on the complexity of its tooth surface, based on the coordinate transformation principle and the spatial meshing theory, a discrete algorithm of this tooth surface was proposed. The determination rule of the limiting points on the tooth surface was analyzed by introducing the generating method and tooth surface characteristics of this gear tooth. Through the corresponding limiting angles and the distribution law of the contact line, the gear tooth surface was discretized, and the theoretical data points of the tooth surface was obtained. The variations of gear tooth surface in a meshing cycle and under different parameters were analyzed, respectively. By comparing with the virtual tooth model and the corresponding rolling experiment, the correctness of the tooth surface discrete algorithm of curve-face gear was verified.