The invention discloses a slope trimming device. The slope trimming device comprises a mounting plate, wherein the mounting plate is arranged on a base plate; the mounting plate is detachably connected with the base plate; stand columns are arranged close to the lower surfaces of the two side surfaces of the base plate; the two stand columns are fixedly connected with the base plate and are arranged on a trimming plate; the trimming plate is movably connected with the two stand columns; a partition plate is arranged on the lower surface of the base plate and is clamped with the base plate; a movable plate is arranged on the lower surface of the partition plate and is formed by splicing two plate bodies; two compression springs are arranged inside the movable plate, are respectively arranged close to the stand columns and are provided with adjusting parts; the adjusting parts are horizontally arranged on the compression springs; one end of each adjusting part is connected with each compression spring. The slope trimming device is capable of better trimming roadbed slopes and enabling the roadbed slopes to be relatively linear and straight, and is flexible in adjusting performance, simple to operate and convenient to maintain; the working efficiency is effectively improved; the labor intensity is alleviated.