The invention discloses a pair of windproof and rainproof trousers. The windproof and rainproof trousers comprise a windproof and rainproof trouser body, wherein the windproof and rainproof trouser body comprises a trouser waist and a trouser body, the trouser waist and the trouser body are connected with each other, and the trouser body comprises two trouser legs. A detachable inner leg opening is arranged on the lower portion of the inner side of each trouser leg, wherein the two sides of the inner leg opening which is unfolded are provided with a hook-and-loop fastener rough surface and a hook-and-loop fastener hook surface respectively, and an elastic cord is arranged at the bottom end of the inner leg opening. The windproof and rainproof trousers are simple in structure, good in heat retention, high in safety and reliability, high in comfort level after being worn on a human body, good in hip lifting effect, attractive in appearance, high in practicability, and good in breathability and heat dissipation effect.