Winter trousers for protecting knees during riding in winter

The invention discloses a pair of winter trousers for protecting knees during riding in winter. Thickening sleeve layers are connected to the parts, two centimeters above the knees, on the left trousers leg and the right trousers leg of the winter trousers; a slide fastener is arranged on each thickening sleeve layer and controls the opening and closing of the thickening sleeve layer; an upper loop of each thickening sleeve layer is of an elastic structure; a lower loop of each thickening sleeve layer is fixedly connected with the corresponding trousers leg; a thermal insulation sheet is arranged on each thickening sleeve layer. The winter trousers are mainly characterized in that protecting knees and the trousers legs are integrally connected in an up and down turning way; the thickening sleeve layers are closed and opened by the slide fasteners; the winter trousers are convenient to use, quick in use and attractive and elegant in appearance.