The invention relates to the technical field of solar water heaters and discloses a solar heat-collection plate which comprises at least a splice plate. The splice plate is provided with at least a pipeline. The pipelines extend longitudinally along the splice plate and are arranged side by side. The transverse ends of the splice plates are sequentially spliced side by side, the longitudinal front and tail ends of the splice plates are sequentially communicated to form an S-shaped liquid flow channel and a liquid inlet end and a liquid outlet end are respectively formed at both ends of the S-shaped liquid flow channel. The machining technology of the solar heat-collection plate is quite simple and the production efficiency is higher. Besides, the pipeline of the solar heat-collection plate is not formed by huffing, and the pipeline wall is thicker and can bear greater pressure. The invention also discloses a solar heat collector and a solar water heater.