The invention belongs to a permanent-magnet synchronous motor control technology, and relates to a high-voltage permanent-magnet synchronous motor closed-loop soft-start method. According to the technical scheme adopted in the invention, the method comprises the following steps: at the moment when a 540V voltage is applied to the bus of a motor, a microprocessor sets a given speed to a small value; the microprocessor calculates the real-time speed of the motor according to the mechanical displacement of a motor position sensor; the microprocessor executes a speed closed-loop control strategy; the microprocessor detects whether the difference between the given speed and the real-time speed is smaller than a given tolerance, adds a value to the given speed if the difference between the given speed and the real-time speed is smaller than the given tolerance, and continues executing the speed closed-loop control strategy if the difference between the given speed and the real-time speed is not smaller than the given tolerance; and the same steps are repeated until the microprocessor changes the given speed to a final expected value. The problem that there are current spikes at the moment when the bus of a high-voltage permanent-magnet synchronous motor is powered on is solved effectively, the requirement of the system for transient response is satisfied, and rapid motor soft-start is realized.