The performance and stability of underwater wet-mate connectors are of great significance for guaranteeing the long - term reliable operation and safety of subsea engineering systems. In recent years， while some domestic research institutions and enterprises have successfully developed prototype models based on relevant principles， domestic products still face the challenge of insufficient market recognition in the competition. This is due to the lack of efficient， low-cost， and full-life-cycle system testing methods， dedicated equipment， and a comprehensive sea-trial verification system. This paper commences from the perspective of enhancing the reliability of domestically-produced underwater electric-optical hybrid wet-mate connectors. A systematic series of tests were carried out on the self-developed connector prototypes， and a set of automatic connecting test devices suitable for underwater pressure environments was successfully developed， enabling automatic cyclic mating and demating operations of the connectors. The outcomes of sea trials indicate that the self-developed connectors successfully accomplished 100 consecutive mating and demating operations at a water depth of 2 960 meters， and all performance indicators met the technical requirements of relevant foreign standards， attaining an international advanced level.