Nowadays humans are concerned more about their privacy because traditional text password becomes weaker to defend from various attacks. Meanwhile, somatosensory become popular, which makes gesture authentication become possible. This research tries to use humans dynamic hand gesture to make an authentication system, which should have low limitation and be natural. In this paper, we describe a depth camera based dynamic hand gesture authentication method, and generate a template updating mechanism for the system. In the case of simple gesture, the average accuracy is 91.38%, and in the case of complicated gesture, the average accuracy is 95.21%, with 1.65% false acceptance rate. We have also evaluated the system with template updated mechanism.