Abstract: To achieve deep recovery of waste heat and resource utilization of the working fluid from the continuous blowdown water of subcritical coal-fired unit boilers, an advanced recovery process based on enthalpy difference compensation and purification was developed and validated. Taking a 2×330 MW unit in a power plant as the research object, a technical route was designed and implemented. This route employs turbine extraction steam as the heat source for enthalpy difference compensation vaporization of the blowdown water, utilizes a dual-path dual-adjustment vaporizer for precise flow control, and incorporates a purification system with three-stage filtration （high-temperature precision filtration, inertial separation, and nanomaterial adsorption） to ensure the output steam meets the quality requirements for heating. The results show that the system successfully converted the entire average blowdown water flow of 22.09 t/h into qualified steam, achieving 100% recovery of both heat and working fluid. This technology effectively addresses the key challenges of deep waste heat recovery and purification of salt-alkali crystallized substances from blowdown water, demonstrating significant energy-saving, carbon reduction, and economic benefits, thereby providing a valuable engineering model for resource recycling in similar units.