Abstract: Objective To design a dental prosthesis retention pin and post system with better biomechanical function. Methods According to the actual biological stress of retention pin and post system in oral cavity,design a new pin and post structure,and carry on experiment on teeth in vitro. Results The designed twoway bone threaded retention pins with Φ 0.75 could improve the retention force by 30~140 N,and the steps could further improve resistance to chewing force by 20~50 N. Conclusions The pin and post system can increase the value of resistance to chewing force,reduce the harm to tooth dentin caused by metal with high modulus of elasticity,improve the repair and retention effect,and extend the life of retention.