The work aims to design a two-way valve to make it normally run over 2 years (5000 h) without failure. Based on the Ansys Workbench simulation software, the explicit dynamics and fatigue for the valve core that impacted the cover plate were analyzed. Weak links of the two-way valve were obtained. Optimization design and contrastive analysis were conducted for key vulnerable elements. When the diameter of the minimum cross section of the valve core was changed from 24.5 mm to 28 mm without affecting the sealing performance of the two-way valve, the optimized two-way valve was able to run continuously for 5000 h without fatigue damage. In conclusion, fatigue analysis is carried out to after explicit dynamics of two-way valve is analyzed and then the maximum stress obtained when the valve element impacts the cover plate is applied to the valve element. Therefore the results of analysis are more reliable.