The invention discloses a high-power soft package battery injection liquid and a manufacturing method thereof. The device comprises a supporting frame, a liquid injection table used for being in buttjoint with an assembly line, a liquid injection mechanism, a stripping mechanism, a capping table, an equivalent filling mechanism and an assembly line butt joint mechanism. The liquid injection tableis installed in the middle of the outer side of the supporting frame. The liquid injection mechanism is mounted in the middle of the liquid injection table; the stripping mechanism is arranged on theright side of the liquid injection table; the capping table is mounted at the top of the outer side of the supporting frame; the equivalent filling mechanism is arranged in the middle of the top of the capping table; the assembly line butt joint mechanism is installed on the left side of the middle of the liquid injection table. According to the high-power soft package battery injection liquid and the manufacturing method thereof disclosed in the invention, moving and liquid injection operation are carried out in a longitudinal direction, certain distance compensation is added for soft package battery liquid injection on the assembly line, the moving rhythm of the assembly line is better adapted, the purposes that the rhythm of the assembly line is not affected and the production efficiency is improved are achieved, and the economic benefits of soft package battery liquid injection on the assembly line are effectively improved.