Existing coordination control methods and equipment for hybrid AC/DC microgrids (HMG) often struggle to balance operational economy and system security under source-load uncertainties. To address this issue, considering both steady-state and fault conditions, this paper proposes a multimode coordination control strategy for hybrid transformer (HT)-interconnected hybrid AC/DC microgrids (HT-HMG) based on multiple time scales. First, the HT-HMG topology structure is designed, and the HT-HMG system is divided into shunt, series, and island modes according to the operating conditions of the distribution network. A “normal-fault” zoning and hierarchical control system for HMG is constructed using the HT as the key regulating component. Then, starting from multiple time scales, energy management optimization strategy and power coordination control strategy under multiple operating modes are proposed. For steady-state operating conditions, a long-term energy management optimization strategy with the objective of maximizing operating revenue is proposed to improve the economic efficiency of HMG operation. For fault conditions, a real-time power coordination control strategy based on HT emergency voltage support is proposed, enabling fault isolation at transformer nodes to enhance system security. Finally, the feasibility and effectiveness of the proposed HT-HMG multimode coordination control strategy are verified through simulations.