The invention discloses a blade profile clamping device for machining of a precision forging blade of an aero-engine. The blade profile clamping device comprises a fixed clamping base; one side of thefixed clamping base is connected with a moving clamping base, the fixed clamping base is movably connected with a first fixed compaction mechanism, and a second fixed compaction mechanism is movablyconnected with the moving clamping base; a first blade profile fixed supporting block and a second blade profile fixed supporting block are arranged on the fixed clamping base, and a first blade profile type floating compaction mechanism for compressing the blade is connected with the first fixed compaction mechanism; and a first blade profile moving supporting block and a second blade profile moving supporting block are arranged on the moving clamping base, a second blade profile floating compaction mechanism for compressing the blade is connected to the second fixed compaction mechanism, anda flange plate positioning block for positioning the edge plate end of the blade and an air inlet edge positioning block for positioning the air inlet edge of the blade are further arranged on the fixed clamping base. The blade profile clamping device satisfies the requirements of being low in clamping deformation, high in clamping rigidity and being without pressing and damaging the blade.