Dielectric heating (DH) technology, including microwave and radio-frequency heating, is a type of advanced heating achieved through electromagnetic fields at specific frequencies. DH technology is widely used in the processing of various agricultural products and industrial-scale production owing to its green, efficient, and low-carbon nature. This paper reviewed the principles, typical systems, and devices of the DH technology. The mechanism and application of the DH technology in the processing of agricultural products are described. The research progress, application prospects, future research strategies, and limitations of DH technology in the multi-objective processing of agro-products were highlighted. Compared with traditional heating methods, DH with rapid, volumetric, and selective heating achieves good performance in drying, pasteurization, disinfestation, enzyme deactivation, and improvement of seed germination while producing high-quality agricultural products. Studies have shown that DH technology can simultaneously achieve multi-objective processing, which reduces processing steps, costs, and carbon emissions and raises economic returns. DH technology assisted in multi-objective processing could extend the shelf life and avoid spoilage of products during storage. Future research needs to be conducted with the help of computer simulations and artificial intelligence for parameter optimization and quality improvement to realize multi-objective DH technology in industrial applications.