In this paper, the finite element simulation software COMSOL is used to calculate the band-gap of the two-dimensional chiral phononic crystal, and the influence of the scatterer parameters and ligament coating parameters on the band-gap is analyzed. On this basis, the effective parameter design space for the optimal design of the band-gap of chiral phononic crystals is determined; then, based on the ISIGHT optimization design platform, the genetic algorithm is embedded to carry out the optimal design of the band-gap of two-dimensional chiral phononic crystals. In the optimal design process of the band-gap, the effective configuration parameters of the two-dimensional chiral phononic crystal are used as the design variables, and the maximum relative band-gap width is the goal to design the unit cell configuration of the chiral phononic crystal. Then, the optimized unit cell configuration is used as the initial configuration, the effective material parameters of the chiral phononic crystal are used as the design variables, and the maximum relative band-gap width is the goal to further realize the optimal design of the band-gap of the two-dimensional chiral phononic crystal. This work maximizes the potential of optimal design of the band-gap of two-dimensional chiral phononic crystals, and provides a reliable and effective analysis and design method for giving full play to the role of chiral phononic crystals in vibration and noise reduction.