The experimental and numerical results on two kinds of gear impact were compared: (1) Gear rigid impact system within backlash, assuming the teeth of the gearwheels come into contact only for a very short time and the boundary is rigid; (2) Gear elastic impact system containing elastic constraint and backlash, in which the driven gearwheel can move freely between backlashes, and the boundary is elastic and expressed with no-mass-spring-dashpot. The dynamic responses of two kinds of gear impact models were compared by experimental and numerical analysis. Firstly, the correctness of the mechanical models was verified through experimental analysis. Then, the results of the numerical and experimental analysis were compared.