According to the requirements of seal bonding and working environment for valve assemblies of extravehicular activity （EVA） spacesuits，the adhesive selection and optimization，performances in typical environments， the structure design of the bonding surface of typical bonding samples and the optimization of the bonding process were carried out on three toughened epoxy adhesives HXJ-14， HYJ-51 and FHJ-75. The results show that HYJ-51 adhesive has good bonding properties， resistance to alternating temperature cycles， resistance to humidity and medium immersion， and therefore meets the sealing and bonding requirements for EVA spacesuits. For the typical valve assembly bonding， the gap between the PTFE slide and the stainless-steel valve body is designed to be 0.1 to 0.15 mm. An annular groove structure added to the bonding surface of the stainless-steel valve body， which can effectively reduce the defects of the bonding surface， avoid the formation of penetrating channels， improve the sealing reliability of the valve assembly bonding， and consequently meet the design requirements of the valve assembly.