A device for automatically adjusting the working width of a first plow body (111) of a plow (1) according to the variable working width of the following plow bodies (112, 113), being a crossbar ( 1112) of each plow body (111, 112, 113) attached to a rear section of the frame (117), pivoting about a second vertical pivot axis (115) and being connected to a parallel rod (114) that is anchored to a front section of the frame (116) through a lateral displacement section (118), in which a first hydraulic cylinder (13) is arranged to laterally displace the rear section of the frame (117) with respect to the front section of the frame (116), the first hydraulic cylinder (13) and two parallel rods (1181, 1182) forming a connection between the front section of the frame (116) and the rear section of the frame (117), and a second hydraulic cylinder ( 14) is forming a The connection between the rear section of the frame (117) and the lateral displacement section (118) and is arranged to pivot the rear section of the frame (117) around a first vertical pivot axis (119) arranged in the connection between the front section of the frame (116) and the rear section of the frame (117) to thereby adjust the cross spacing of the plow bodies (111, 112, 113) by pivoting the plow bodies (111, 112, 113 ) around second vertical pivot axes (115), characterized in that the first hydraulic cylinder (13) is a multi-stage cylinder in which a first cylinder stage (131) forms a main lateral control, and a second stage of cylinder (132), which extends from inside the first cylinder stage (131), forms an automatic control of the working width for the first plow body (111), the second cylinder stage (132) being in communication n of hydraulic fluid with the second hydraulic cylinder (14) in a configuration from main to secondary, the second stage of the cylinder (132) being the main or secondary depending on the direction of movement of the stage of the cylinder (132), and correspondingly, the second
