Abstract: The HXD3B electric locomotive is a high-power AC drive mainline freight locomotive with six axles,developed to meet the heavy-haul transportation demands of Chinese railways.It utilizes three-phase AC asynchronous motors for traction.This paper investigates the frequent failure phenomenon of stator winding burnout in HXD3B traction motors,analyzing its root causes and proposing improvement measures,including optimized motor maintenance procedures and enhanced winding structural design.Practical operational validation confirms that the implemented modifications significantly enhance motor reliability,effectively resolving the persistent issue of winding thermal