The invention relates to a loophole fingerprint based vulnerability code clone detecting method and device. The method includes steps of collecting a code sample, and building a loophole database; selecting the loophole and searching the loophole patch information, and acquiring a vulnerability code sample; structuring a code analyzer; pretreating the vulnerability code sample by means of the codeanalyzer to obtain a standard middle expression; dividing the middle expression to be a code block with size of s line; calculating a characteristic value of the code block through a hash function, and combining to generate the loophole fingerprint; pretreating the code to be detected by means of the code analyzer and acquiring a characteristic value sequence of the code to be detected; mapping the loophole fingerprint to n bit of bit drawing; identifying if the characteristic value sequence is existed with vulnerability code clone by means of the bit drawing and outputting it. The method anddevice can effectively deal with the common code modifying method in the code cloning, well balance the relationship between the detecting efficiency and the detecting accuracy, and effectively detect the large-scale objects while keeping good accuracy.