The suspension electromagnets on current normal conductor-based high-speed maglev vehicles adopt direct current (DC) excitation, which belongs to DC electromagnetic suspension. The suspension electromagnets on maglev vehicles also can adopt alternating current (AC) excitation, and AC electromagnetic suspension has comparative advantages in contactless power transfer and field-oriented control. Therefore, it has the technical potential to enhance the performance and reduce the cost of the normal conductor-based high-speed maglev transportation system. However, AC electromagnetic suspension faces technical challenges including the spatiotemporal imbalance of the electromagnetic forces and the capacity of the mover motor controller. This article analyzes the principle and technical characteristics of AC electromagnetic suspension and introduces the development status in this field, the practical exploration process, and the phased achievements. Then, the article discusses the potential technical advantages and challenges of applying AC electromagnetic suspension to high-speed maglev transportation and provides follow-up research and development suggestions.