At present， grain drying methods are limited by environmental and artificial conditions， which greatly restricts the development of the grain processing industry. Therefore， seeking efficient drying technology and equipment has become an important goal for the development of the grain processing industry. This paper summarizes the research and application status of air source heat pump drying technology and equipment at home and abroad. Taking the equipment structure and working principle of air source heat pump drying technology as the research object， it analyzes the reasons for problems such as uneven drying， high energy consumption， and low efficiency in drying equipment and discusses the corresponding improvement methods. It also discusses the advantages and disadvantages of combined drying technology compared to single drying technology in terms of equipment， processes， and other aspects. Based on research directions， improvement of joint drying processes， construction of drying information platforms， and equipment research and development policies， the development of joint drying technologies in the field of grain drying is expected to provide a reference for the development and equipment innovation in the drying field.