The invention relates to a heat-resistant clothing hot melt adhesive, which is characterized by comprising the following components by mass percent: 29-46.45% of hot melt adhesive, 26.1-45.52% of PE, 0.29-2.32% of bulking agent, 0.29-2.32% of sensitizer or sensitizing agent, 0.95-9.9% of nanoscale montmorillonoid or nanoscale clay, 0.05-0.5% of compatilizer, 5-20% of tackifier, 1-10% of plasticizer and 0.1-2% of antioxygen, wherein the hot melt adhesive is one or more combination of PET, PA, TPU and EVA. The preparation method comprises the following steps: 1) adding the PE, bulking agent, sensitizer or sensitizing agent into a blender and mixing for standby use; 2) adding the compatilizer and nanoscale montmorillonoid or nanoscale clay into the blender, and mixing for standby use; 3) adding the hot melt adhesive into the blender, and mixing with the blending materials obtained in the step 1 and 2; 4) slowly pouring the tackifier, plasticizer and antioxygen and mixing the materials; and 5) pelleting the obtained blending in the step 4, cooling and dicing to obtain the heat-resistant clothing hot melt adhesive. The preparation method of the invention is simple in process, and the obtained hot melt adhesive has good flexibility, adhesiveness and thermal stability.