The invention relates to the technical field of kitchen utensils for cooking foods in steam, and discloses a steam food processor with an effective non-return effect.The steam food processor comprises an upper body and a lower body.The upper body comprises an inner pot and a lid, the lower body comprises a base, a control circuit and an outer pot, a steam generator is arranged in the base, a steam valve is hermetically connected with the bottom of the inner pot and comprises a sprayer and a valve seat, a vertical blind hole is formed in the lower end of the sprayer, a through hole is formed in the valve seat and is coaxially hermetically communicated with the blind hole, a first sealing ring is hermetically matched with the through hole of the valve seat, a ball and a compression spring are arranged in the blind hole, one end of the compression spring is butted to the bottom surface of the blind hole, and the other end of the compression spring is butted to the ball, so that an opening of the first sealing ring can be sealed by the ball; a steam spray nozzle of the sprayer is communicated with the blind hole, and the through hole of the valve seat is communicated with a steam outlet of the steam generator.The steam food processor has the advantages that good sealing effect and the non-return effect can be realized, the steam pressure adjustable ranges can be expanded, and accordingly foods cooked by the aid of the steam food processor are nutritious and delicious.