This paper presents a new methods that enhance the image of hand vein based on contrast limited local histogram equalization(CLAHE) and top-hat transform to overcome the influence of photoelectric and thickness of the back of hand skin.After making CLAHE process,top-hat transform is used to extract the peak and trough of the image.And the peak and trough which are made histogram equalization to extend gray distribution do addition and subtraction with the image making CLAHE process.The experiments show that the algorithm can make a very clear enhancement.