Method for locking a dual clutch transmission of a work vehicle, said dual clutch transmission essentially comprising: • an engine input shaft configured to be coupled to the output of an engine of said work vehicle, • a shaft configured to be coupled to a drive system of said work vehicle and • a forward clutch and a rearward clutch, each configured to be coupled to the engine input shaft; • first and second intermediate shafts (11, 12) each configured to carry a plurality of gears (14, 15), said first and second intermediate shaft (11, 12) being configured to be coupled, via respective first and second clutches (7, 8), to said forward clutch and to said rearward clutch and being configured to be coupled to said shaft defining with one of said gears (14, 15) a predetermined speed ratio between said engine input shaft and said shaft, each of said gears (14, 15) defining a different predetermined speed ratio among them between said engine input shaft and said shaft, said locking method being characterized by comprising the following phases: • a first decelerating phase in which the vehicle speed is reduced until a predetermined velocity while a gear of said plurality of gears (14, 15) is coupled to said shaft to give a driving torque to one of said first and second shafts (11, 12); • a second phase in which said vehicle is maintained at said predetermined velocity; • a third phase in which a gear of said plurality of gears (14, 15) of the other of said first and second shafts (11, 12) is engaged; • a fourth phase in which said first and second clutches (7, 8) are both engaged in order to block said dual clutch transmission; and • a fifth phase in which said forward and rearward clutches (5, 6) are disengaged and said input shaft is consequently decoupled from said dual clutch transmission. • an engine input shaft configured to be coupled to the output of an engine of said work vehicle, • a shaft configured to be coupled to a drive system of said work vehicle and • a forward clutch and a rearward clutch, each configured to be coupled to the engine input shaft; • first and second intermediate shafts (11, 12) each configured to carry a plurality of gears (14, 15), said first and second intermediate shaft (11, 12) being configured to be coupled, via respective first and second clutches (7, 8), to said forward clutch and to said rearward clutch and being configured to be coupled to said shaft defining with one of said gears (14, 15) a predetermined speed ratio between said engine input shaft and said shaft, each of said gears (14, 15) defining a different predetermined speed ratio among them between said engine input shaft and said shaft, • a first decelerating phase in which the vehicle speed is reduced until a predetermined velocity while a gear of said plurality of gears (14, 15) is coupled to said shaft to give a driving torque to one of said first and second shafts (11, 12); • a second phase in which said vehicle is maintained at said predetermined velocity; • a third phase in which a gear of said plurality of gears (14, 15) of the other of said first and second shafts (11, 12) is engaged; • a fourth phase in which said first and second clutches (7, 8) are both engaged in order to block said dual clutch transmission; and • a fifth phase in which said forward and rearward clutches (5, 6) are disengaged and said input shaft is consequently decoupled from said dual clutch transmission.