An experimental scheme is proposed to recover the waste heat of power plant circulating water to dry lignite with heat pump, and the experiment system was developed. Experiments of drying lignite in the temperature of 60℃, 70℃and 80℃ were conducted, and the change of lignite quality with time was measured. The result shows that: the higher the temperature ,the faster drying rate; the longer the effective drying time ,the better the result. Drying 22.5% water at the temperature of 60℃ takes time 25 min; 30.5%-31.5% at 70℃takes 30 min; 42.6% at 80℃ takes 35 min. This paper provides a reference for the practical application of heat pump in the utilization of waste heat of circulating water for drying lignite.