The controlled dispersion of a magnesium fluoride crystal resonator was studied to optimize the performance of the whispering gallery mode （WGM） resonator and the quality of generated optical frequency combs （OFCs） based on the WGM optical resonator. Firstly， the effect of the edge shape of a MgF₂ crystal resonator on the cavity mode field and total dispersion was investigated by theoretical simulation. Thereafter， two kinds of MgF₂ crystal resonators were fabricated according to the simulation results， namely plane edge and unilateral wedge types， respectively. The resonator performance detection and crystal resonator optical frequency comb generation systems were established， and the quality factor （Q factor） of the processed MgF₂ crystal resonator samples was recorded up to $\mathrm{1.1}\times {\mathrm{10}}^{\mathrm{8}}$. Finally， the Kerr optical frequency comb， with a wide spectral range of more than 200 nm， was excited in both the planar crystal resonators. The experimental results verified that the edge-wedged micro-resonator structure could effectively compress the mode field and regulate the total dispersion. In addition， a wider spectral range of the OFC could be produced in comparison with the edge-flat micro-resonator.