WORK VEHICLE AND CONTROL METHOD FOR WORK VEHICLE

A work vehicle includes: a power transmission device that includes a hydraulic transmission mechanism including a first hydraulic pump motor and a second hydraulic pump motor and transmitting power input to an input shaft to an output shaft via a clutch mechanism; and a control device. The control device includes: a clutch control unit that outputs a clutch command for engaging a specified clutch among a plurality of clutches of the clutch mechanism based on a speed ratio indicating a ratio between a rotation speed of the input shaft and a rotation speed of the output shaft; a storage unit that stores correlation data indicating a relationship between the speed ratio and a capacity of the first hydraulic pump motor and a capacity of the second hydraulic pump motor; and a power control unit that outputs a capacity command for changing at least one of the capacity of the first hydraulic pump motor or the capacity of the second hydraulic pump motor based on the speed ratio and the correlation data. The correlation data is set so that both the capacity of the first hydraulic pump motor and the capacity of the second hydraulic pump motor are changed with a change in the speed ratio in a predetermined speed ratio range between a first speed ratio and a second speed ratio higher than the first speed ratio.