The invention discloses a steam waste heat recycling device. The steam waste heat recycling device comprises a shell. The shell is internally provided with a first cavity used for containing cooling water and a second cavity used for circulation of waste heat steam. The first cavity and the second cavity are isolated through a flat plate heat transfer structure. The flat plate heat transfer structure comprises an upper end panel, a lower end panel and a phase change working medium in a cavity between the upper end panel and the lower end panel. According to the above technical scheme, after the phase change working medium absorbs waste heat of the waste heat steam, the phase change working medium is evaporated and transferred to the hydrophilic face of the upper end panel through the hydrophilic face of the lower end panel, heat releasing and condensation are achieved on the hydrophilic face, the heat releasing process is the process of transferring heat to cooling water, and the waste heat of the waste heat steam can be recycled through the repetition of the process. Accordingly, in the phase change working medium evaporation and condensation process, the heat transfer efficiency is greatly improved, and waste heat recycling is more sufficient and more efficient.