A micro projector driving device and a driving method are provided, where pixels of the first and last images at a specified location are compared, and the light intensity of the light sources is then adjusted according to the compared results so as to avoid the continual display of images with different contrast requirements at the highest light intensity, thus saving power under a guaranteed visual effect, and prolonging the battery life of a portable micro projector. A higher power drive light source should be used for a static image rather than for a video image. Images are divided into sections, and then the pixels from each section are selected at random for comparison, therefore greatly reducing the amount of computing but still having a rather high accuracy.