According to an embodiment, there is provided a sheet finishing apparatus including a folding roller that nips the middle of bundle of sheets and forms a fold line, a fold reinforcing roller that reinforces the fold line by moving along the fold line while applying a pressure to the fold line, a stack tray that stacks the bundle and a control unit that sets the number of times of fold reinforcing performed by the fold reinforcing roller as a first number when it is determined that a quantity of stacked bundle on the stack tray is less than a predetermined standard quantity which is set to be less than a maximum stack quantity and sets the number of times of the fold reinforcing as a second number greater than the first number when it is determined that a quantity of the stacked bundle is greater than the predetermined standard quantity.