Abstract: This paper focus on the digital watermark technology and try to protect the copyright and securities of Mount Helan rock painting. In order to prevent the 2D relic data shared in Internet from being illegally copied or used with some other purpose, this algorithm batch embed the same color images as watermark information into the relic images. The algorithm finished discrete cosine transform by using FDCT and embedded low frequency and intermediate frequencyt of watermark into intermediate frequency of relic image. The result indicates that the algorithm is rapid and robustness.