Cover Story：Microwave-induced thermoacoustic imaging (TAI) is an emerging new imaging technology. This article opens a new direction for this technology to image human thyroid. The thermoacoustic system used in this study consists of a pulse microwave source, flexible array detectors, a customized thyroid stent, multi-channel data acquisition devices and a data reconstruction system. We described the basic theory of microwave-induced thermoacoustic imaging and discussed theoretically the feasibility of this thermoacoustic system for human thyroid imaging. Thermoacoustic imaging experiments were performed on the healthy thyroid of three volunteers. The results showed that the system can clearly image the healthy thyroid gland and truly reflect the structural characteristics of different tissues including the skin, thyroid and trachea. A complete data collection process takes about 5 seconds, and therefore, the system operation is simple and fast. This study indicates that TAI may become a new imaging tool for basic research and clinical diagnosis of thyroid diseases.