Abstract: Disclosed are a device and a method for measuring a Soret coefficient. The device comprises a control component, a diffusion mechanism, a temperature regulating component and a circulation mechanism. The diffusion mechanism comprises a liquid flow tank; the side wall of the inner cavity of the liquid flow tank is fixedly connected with an insulating layer; the side wall of that liquid flow tank is communicated with a plurality of liquid taking components; the circulation mechanism comprises a transfer unit, a cooling component and a heating unit; a temperature regulating component is fixedly connected between the liquid flow tank and the cooling component; the bottom surface of the heating unit is fixedly connected with the top surface of the liquid flow tank; the cooling component and the heating unit are respectively communicated with the transfer unit; the transfer unit is electrically connected with the control component.