Abstract: To address the issues of thermal loss and resource waste caused by continuous blowdown in subcritical coal-fired unit boilers, and in response to national energy conservation and water-saving policies, tan efficient technological pathway for simultaneous heat and mass recovery is explored. Focusing on a 330 MW unit as a case study, the research involved the design of a purification and recovery process based on the enthalpy difference compensation principle. By developing a thermodynamic calculation model, the efficiencies of three schemes—flash evaporation, heat exchange, and enthalpy difference compensation—were compared, and process validation was employed to analyze the system’s feasibility and parameter compatibility. The results indicate that this technology can completely convert blowdown water into qualified steam for heating, achieving a recovery efficiency of nearly 100%. It is projected to annually recover an additional 13.58 GJ/h of heat and 22.09 t/h of water, yielding an estimated annual profit of 6.6366 million RMB after accounting for operational costs, demonstrating significant economic benefits. In conclusion, the enthalpy difference compensation recovery technology exhibits strong technical feasibility and economic attractiveness for subcritical coal-fired units, offering an effective engineering solution for power plants to achieve energy saving, emission reduction, and cost optimization.