The Maevatanana gold deposit in Madagascar is a quartz-vein type gold deposit hosted in a greenstone belt, and its genesis is highly controversial. This article conducts elemental geochemical analysis and dating of the Maevatanana gold deposit, and explores the mineralization age and process of the Maevatanana gold deposit in Madagascar. The gold content of gneiss is 1.11×10^-9~80.8 ×10^-9, with an average of 19.55×10^-9; pyrite is the main gold-bearing mineral in gneiss, with a Re-Os isotopic age of 752±27 Ma. The gold grade of the gold-bearing quartz vein is 26.44×10^-6~132.22×10^-6, and pyrite is the main gold-bearing mineral. The Re-Os isotopic age of pyrite in the gold-bearing quartz vein is 535±26 Ma, representing the mineralization age of the Maevatanana gold deposit. The Re-Os isotope isochron ages of two phases of pyrite correspond to the time of two collisions during the Pan Afri- can orogeny event. The gold content in gneiss is much higher than the average grade of the crust, and encapsulated gold can be seen in pyrite. The Re-Os isotopic age of pyrite indicates intrusion of granite and gabbro at 752±27 Ma. The Madagascar terrane underwent extensive metamorphism from greenschist to amphibolite facies, and gold in volcanic sedimentary rocks was activated, migrated, and enriched to form a source layer. The mineralization age of the gold-bearing quartz vein is 535 ± 26 Ma, which is consistent with the age of the Cambrian post collisional A-type granite in central northern Madagascar. Field evidence and geochemical data indicate a close genetic relationship between the Maevatanana gold deposit and the Cambrian post collisional A-type granite. During the process of magma ascending, the high-Si melts entered the magma and gradually evolved into ore-forming fluids, which enter the host structures and enrich mineralization.