In the vector control system of a Permanent Magnet Synchronous Motor (PMSM) using a T-type three-level inverter, switch faults such as open-circuit or short-circuit faults frequently occur. These faults can cause the original modulation strategy to fail, resulting in three-phase current distortion, speed and torque fluctuations, and severe impacts on system stability. To address these issues, this paper proposes a fault-tolerant T-type inverter topology and a corresponding fault-tolerant modulation strategy. The new topology transforms potential short-circuit faults into open-circuit faults, thereby mitigating the damage caused by short-circuit faults. A fault diagnosis method based on the Mixed Logical Dynamic (MLD) model and current residuals is used to determine the specific fault location of the switches. By classifying faults according to the fault location and number, and when the fault type meets the criteria for the fault-tolerant modulation strategy, the system automatically switches from the original modulation strategy to one suitable for the fault type. Simulation and experimental results validate the effectiveness and reliability of the proposed inverter topology and fault-tolerant modulation strategy in practical applications.