A gear-hydraulic-metal belt integrated multi-mode hydro-mechanical hybrid transmission device includes an input assembly, an output assembly, a metal belt transmission mechanism, a planetary gear assembly, a hydraulic transmission mechanism, a clutch assembly and a brake assembly. The input assembly is connected to the metal belt transmission mechanism, the planetary gear assembly and the hydraulic transmission mechanism. The metal belt transmission mechanism and the hydraulic transmission mechanism are connected to the planetary gear assembly. The planetary gear assembly is connected to the output assembly. The clutch assembly connects the input assembly to the metal belt transmission mechanism and the planetary gear assembly, and connects each of the metal belt transmission mechanism and the hydraulic transmission mechanism to the planetary gear assembly. The clutch assembly and the brake assembly provide a continuous transmission ratio between the input assembly and the output assembly.