Abstract: A flat-plate water-heating photovoltaic/thermal module and a production process thereof are disclosed. The flat-plate water-heating photovoltaic/thermal module includes a frame. The lower surface of the frame is provided with a heat preservation back plate. The upper surface of the frame is sequentially laminated with a glass cover plate, a first photovoltaic cell laminating adhesive, a photovoltaic cell slice, a second photovoltaic cell laminating adhesive, a transparent back plate, a third photovoltaic cell laminating adhesive and a heat absorbing component from top to bottom. A heat preservation cavity is formed between the heat preservation back plate and the heat absorption part.