CONTROL DEVICE FOR WORK VEHICLE, WORK VEHICLE, AND CONTROL METHOD FOR WORK VEHICLE

A work vehicle is provided with a power source, a travel device, and a power transmission device for transmitting power of a power source to the travel device. The power transmission device includes a hydrostatic continuously variable transmission having a relief valve capable of setting a relief pressure. A control device of the work vehicle is provided with a relief pressure setting unit that is configured to set the relief pressure of the relief valve in accordance with a target output value of the travel device.