Abstract: Objective Wheel idling and skidding caused by adverse external conditions（such as rain and snow） present safety risks to urban rail transit operations and significantly reduce passenger comfort. Therefore, it is necessary to conduct an in-depth analysis of the mechanisms, causes and impacts of train wheel idling and skidding during operation. Method Based on the actual operation of Kunming Metro Line 6, the phenomenon of wheel idling and skidding that occur under special environmental conditions is described and analyzed. Through modeling, the mechanisms behind wheel idling and skidding their impact on train operation are examined in detail. On this basis, a segmented stepwise speed limiting optimization method is proposed. Using simulation analysis, the optimal stepwise speed limit ranges and values suitable for practical application are determined. Result ＆ Conclusion During rainy and snowy conditions, wheel idling and skidding are more likely to occur when trains apply a single high-rate brake during station approach. The proposed stepwise speed limiting method allows the train to decelerate in segments, which can effectively alleviate wheel idling and skidding. Through laboratory simulations and field validation, it is demonstrated that, with an appropriate station approach braking rate, segmented stepwise speed limiting significantly improves the braking process, effectively reduces the occurrence of wheel idling and skidding, and enhances operational safety, stability, and comfort under rainy and snowy weather conditions.