ABSTRACT Use of microwave heating has increased in the coarse cereals sector due to its versatility. In order to improve the poor cooking quality and rough mouthfeel of coarse cereals, the effects of microwave treatment on the cooking quality of soaked coarse cereals and sensory score of cooked coarse cereals were studied, and the improvement mechanism was revealed from the aspects of water distribution, starch ordered structure, and microstructure. The microwave treatment significantly improved the quality of coarse cereals. Especially after 480 W microwave treatment for 10 min, the hardness and chewability of coarse cereals decreased from 3162.63 and 378.12 N to 2039.15 and 133.13 N, respectively. The water fluidity was improved and part of the immobile water was transformed into tightly bound water. The microwave treatment promoted a reduction in the values of peak viscosity, final viscosity, breakdown, and setback for samples. Microwave treatment increased the short‐range ordered structure of starch, and scanning electron microscopy showed that the surface of starch particles was rough, with increased cracks and pores. In addition, microwave treatment significantly improved coarse cereals eating quality. The cooking time was significantly shortened, allowing it to be cooked with rice. The texture properties (e.g., hardness, cohesiveness, and chewiness) and sensory properties of cooked coarse cereals were significantly ameliorated by microwave treatment. This study helps to provide a new way for producing high‐quality coarse cereals.