A gear-double ring-hydraulic hybrid transmission device includes an input mechanism, a double ring series transmission mechanism, a hydraulic transmission mechanism, an output member, a front planetary gear mechanism, a middle planetary gear mechanism, a rear planetary gear mechanism, a clutch assembly, and a brake assembly. An output of the double ring series transmission mechanism is connected to the middle planetary gear mechanism. The clutch assembly connects the input mechanism to the double ring series transmission mechanism, the hydraulic transmission mechanism, and the front planetary gear mechanism, connects an output of the hydraulic transmission mechanism to the middle planetary gear mechanism, and connects an output of the rear planetary gear mechanism to the output member. The clutch assembly and the brake assembly provide a continuous transmission ratio between the input mechanism and the output member.