The longitudinal unlocking mechanism was a set of mechanism products for connecting and separating the two halves of the launch vehicle fairing. Its core component， the locking hook， need to be unlocked and assembled repeatedly during acceptance and assembly. The spring was the driving element used for the sparation of the locking hook. In order to improve the reliability of springs， this paper studied the use of aluminum electroplating in ionic liquid to replace the electrogalvanizing with hydrogen embrittlement. The process method was first formed through the typical product trial plating， and then the spring trial production was carried out， and finally the heat environment and the hook lock mechanism test were used to verify the reliability of the springs. The results show that shot peening in the process will cause the spring force to decrease slightly，where as the spring in this state also can meet the environmental adaptability requirements. Repeated unlocking can cause the spring plating layer to wear， and the force will decrease by about 5%， but still meet the design requirements.Spring using aluminum electroplating in ionic liquid can replace electro -galvanizing. The post-treatment of shot peening in process implementation needs to be strictly controlled， and the effect of repeated use on spring coating and force value needs to be concerned.