In this paper, the high heat, high humidity and poor air quality in the coal washing workshop in summer are taken as the research object. A set of energy-saving system for cooling and dehumidification in summer, heating in winter and air supply in the whole year is designed and studied by using heat pump technology, heat pipe technology, post air supply and pollutant control technology. The system recovers the waste heat resources of coal washing wastewater in coal washing plant, and provides summer cold source and winter heat source for coal washing workshop. The fresh air system flexibly switches according to the outdoor environment temperature, and sends fresh air to the workshop throughout the year in the most economical way.