Motorcycle height adjusting device and motorcyle height adjusting method

A motorcycle (1) height adjusting device includes a front fork (13) and a rear suspension (22) capable of changing the relative position between a vehicle body (11) and wheels (14, 21) of a motorcycle (1), and a control device (50) that adjusts a height of the motorcycle (1), which is a height of the vehicle body (11), by controlling the front fork (13) and the rear suspension (22) to change the relative position. The control device (50) changes a motorcyle height change rate, which is a rate of changing the motorcycle height to a target motorcycle height during stoppage, on the basis of deceleration of the motorcycle.