A railway vehicle, and a control method and system for a tread profile of a railway vehicle. The control method comprises: step S1, obtaining a lateral acceleration signal of a wheel set; step S2, determining whether a first number of continuous peak values greater than or equal to a first set value present in the lateral acceleration signal or not, and if yes, executing the following step S3; step S3, controlling a tread modification device of a corresponding wheel set to enter a modification mode; step S4, determining whether a first action condition is satisfied or not, and if yes, executing the following step S5; step S5, controlling the tread modification device to perform online state repair on tread profiles of wheels of the corresponding wheel set; step S6, determining whether a second number of continuous peak values less than or equal to a second set value present in the lateral acceleration signal or not, and if yes, executing the following step S7, the second set value being less than the first set value; and step S7, controlling the tread modification device of the corresponding wheel set to exit the modification mode. By means of the control method, an off-line lathing cycle of wheels can be extended.