Bionic walking mechanism is an important part of bionic motion machinery. According to the characteristics of biped walking, a new biped-imitating walking mechanism called Half-Rotating Walking Mechanism (HRWM) was developed using Half-Rotating Mechanism (HRM) which can generate asymmetrical motion. The drive way and walking principle of HRWM were firstly introduced. On the basis of deducing kinematical equations of HRWM, some main factors of ride comfort were presented, which include a new factor named relative amplitude that could be used to valuate the ride comfort of various walking mechanism. The optimization model of HRWM structure was then proposed, which took parameter relationship as design variable. The optimized result could be applicable to different size HRWM. Finally, the calculating result shows that HRWM with optimized parameter relationships has good performance on ride comfort in the process of walking.