The invention discloses an adjustable cotton straw pull-out force measurement device which comprises a rack base (16), a reducer motor (9), guide rails (14) that are arranged on the rack base (16), awinding wheel (11) arranged on an output shaft of the reducer motor (9), self-locking slide blocks (13) arranged on the guide rails (14), a rack (8) arranged on the self-locking slide block (13), a pulley support frame (7) arranged on the rack (8), a V-shaped pulley (6) arranged on the pulley support frame, a pull-out rod (4), a steel wire rope (5) connected with the pull-out rod (4) and the winding wheel (11), a tension sensor (3) arranged between the pull-out rod (4) and a pull-out clamping mechanism (2), a data acquisition card (17) connected with a signal output end of the tension sensor (3), and a pull-out knife (1) arranged on the pull-out clamping mechanism (2). The rack base (16) is fixed with worm support seats (12) via lock nuts (15), and the reducer motor (9) is fixed on the rack base (16) via a motor support seat (10). The device has the advantages that the device is relatively simple in structure, and good in outdoors adaptability and can effectively reduce labor intensityof manual measurement, and collected data can provide a reference for a design of a pull-out device of a cotton straw harvesting machine.