Climate models still exhibit substantial cold biases over the Tibetan Plateau, with snow cover biases recognized as one of the major contributing factors. By incorporating the effects of standing dead grass stems and topographic relief on snow distribution and snow depletion processes, the snow cover fraction (SCF) parameterization was optimized, reducing positive SCF biases by 63 % and alleviating surface cold biases by approximately 1–2 °C in snow-affected regions.