Method for preventing vehicle from shaking during starting of train in low-constant-speed mode

When the train starts in the low-constant-speed mode, the central control unit compares the actual traction value with the brake maintaining threshold value, if the actual traction value of the train is smaller than the brake maintaining release threshold value, the train output traction force is a set value larger than the brake maintaining release threshold value, and if the actual traction value of the train is larger than the brake maintaining release threshold value, the train output traction force is a set value larger than the brake maintaining release threshold value. The actual traction value of the train is output according to the traction characteristic curve of the traction motor, the time for the train to output a brake release keeping instruction is shortened, smooth transition of different states of the train is achieved, the train is prevented from shaking during low-constant-speed mode hill starting, the comfort level of passengers is effectively improved, and the service life of the traction