At present, there are two main methods for forming the hub tooth surface of crown gear coupling. Forming method I is that, the hob centre makes circular motion around the centre of the displacement circle. While forming method II is that gear shaper centre also makes circular motion around the centre of the displacement circle. Forming method determines the tooth shape, thereby affecting the meshing performance of crown gear coupling. However, the differences in tooth shape generated by the aforementioned two forming methods and their influencing mechanisms remain unclear. Therefore, based on the simulation method of tooth surface machining, the two kinds of hub tooth surfaces were simulated and modelled respectively. Subsequently, geometric tooth contact analysis and loaded tooth contact analysis models were established using meshing theory and finite element method. Finally, the tooth shape, unloaded and loaded tooth contact characteristics of forming methods I and II were compared and analysed, respectively. The results show that under the condition of the same displacement circle radius, the deviation of tooth profile shape of forming methods I and II gradually decreases with the increase of the displacement circle radius, and the maximum deviation reaches 251μm. Moreover, the load sharing among teeth of forming method I is much more uneven than that of II, and the maximum loads are 702.8% and 451.2% more than the minimum loads, respectively. Under the condition of the same crowning amount, the displacement circle radius of forming method II must be greater than that of I, and the difference between them is 200mm. The load sharing among teeth of forming methods I and II are close.