Taking visible light responsive graphite carbon nitride ( g-C3N4) as the support, the basic principles of photocatalytic hydrogen evolution were introduced. The promoting mechanism of loading co-catalyst for photocatalytic hydrogen production activity was summarized. The strategies of controlling g-C3N4 hydrogen production activity by loading co-catalyst were discussed. Combined with relevant cases,the research progress of co-catalyst in promoting g-C3N4 photocatalytic hydrogen production activity was summarized. The regulation methods of surface co-catalyst performance optimization were concluded. The internal relationship between catalytic activity and surface/interface structures were analyzed,and the opportunities and challenges of the current work were pointed out.