The invention discloses a photocatalysis hydrogen production promoter.The promoter is one or a mixture of CoP, Co2P, Fe2P, FeP, Cu3P, ZnP, MoP and MnP.The invention further discloses a photocatalysis system containing the photocatalysis hydrogen production promoter.The photocatalysis system comprises a semiconductor, the promoter, an electronic sacrificial agent and water.The hydrogen production efficiency of the photocatalysis system is extremely high, it is unnecessary to add a surface stabilizer, degassing is not needed, and the photocatalysis system is low in cost and more beneficial for practical application.