The invention discloses outdoor trousers. The trousers comprise a trousers body and a waistline adjusting structure, wherein the trousers body is fixedly connected with the waistline adjusting structure; the waistline adjusting structure comprises an extending and retracting belt and a plurality of adjusting hooks; the adjusting hooks are arranged outside a waist of the trousers body; one end of the extending and retracting belt is connected with the outer side of the waist of the trousers body and the other end is movably connected with the adjusting hooks in the arrangement range of the adjusting hooks; the extending and retracting belt comprises extending and retracting parts and fixing parts; two adjusting rings are arranged on the fixing parts; and the space between the two adjusting rings is the same as the distance between the adjusting hooks. The trousers have the advantages that the trousers can achieve the effect of overcoming the defects of the prior art and are reasonable and novel in structural design.