Direct　Z-scheme　LaNiO3/Mn0.2Cd0.8S　heterojunction　photocatalysts　were　synthesized　in　situ　by　the　introduction　of　Mn2+　ions　in　the　hydrothermal　preparation　of　CdS　using　LaNiO3　nanoparticles　matrix　and　fully　characterized　by　field　emission　scanning　electron　microscope,　powder　X-ray　diffraction,　X-ray　photoelectron　spectroscopy,　UV-Vis　diffuse　reflectance　spectra,　N-2　adsorption-desorption　test　and　electrochemistry　test.　LaNiO3/Mn0.2Cd0.8S　heterojunction　photocatalysis　showed　improved　photocatalytic　evolution　and　stability.　The　photocatalytic　H-2　evolution　over　LaNiO3/Mn0.2Cd0.8S　heterojunction　photocatalysts　reached　to　1　190.3　mu　mol　in　5　h,　which　was　25-fold　and　10-fold　enhanced　compared　with　pure　CdS　and　Mn0.2Cd0.8S.　The　enhanced　performance　of　LaNiO3/Mn0.2Cd0.8S　heterojunction　photocatalysts　was　ascribed　to　the　formation　of　heterojunction　between　LaNiO3　and　Mn0.2Cd0.8S　as　well　as　the　introduced　Mn2+　ion,　which　both　can　inhibit　the　recombination　of　the　photoinduced　electron-hole.　Based　on　the　above　results,　the　direct　Z-scheme　photocatalytic　reaction　mechanism　was　proposed　to　elucidate　the　improved　performance　of　LaNiO3/Mn0.2Cd0.8S　heterojunction　photocatalysts.