A driving method for a bistable display device includes setting a first duration and a second duration according to a frame period; applying a first voltage to a light valve layer in the first duration according to display data, so as to transform the light valve layer from a first state to a second state; and applying a second voltage in the second duration to the light valve layer in the second duration for the light valve layer to transform to the first state. Since the light valve layer of the bistable display device is already at the first state prior to displaying the next image, the light valve layer is not required to reset when switching displayed images, hence reducing the total number of frames required to display each image.