Rollback screen window with adjustable size

The invention relates to the field of doors and windows, and particularly relates to a rollback screen window with an adjustable size. The rollback screen window comprises a screen box (1), a screen window frame (2), a bottom brace and a gauze, wherein the bottom brace comprises a bottom brace main body (3), one end of the gauze is connected with the screen box (1), the other end of the gauze is connected with the bottom brace main body (3), the screen box (1) also comprises a first seal cover (11), the bottom brace also comprises an adjusting device connected to the bottom brace main body (3), the adjusting device comprises a connecting part (6) connected to the bottom brace main body (3) and an adjusting part (7) connected to the connecting part (6), the bottom brace is also provided with a fixed device, and the fixed device can be fixed on the bottom of the screen window frame (2). The length and width of the rollback screen window can be adjusted. The rollback screen window is convenient to install and high in efficiency.