A new kind of watermark-embedding and detecting algorithm based on stationary wavelet transform was proposed. Firstly, the digital watermarking was transformed randomly (Arnold transformation), and then encrypted by chaos. The encrypted watermarking was transformed to one-dimensional row vector, and the pixel value was sorted. The coefficient of primitive image of stationary wavelet transformation was expanded to one-dimensional row vector, too, and then the sorted watermarking was embedded to the sorted low frequency and turned to two dimensions. Secondly, the image is reconstructed by coefficients of high-frequency. The process of watermarking extracted is the inversion of the process of watermarking embedded. Finally, the watermarking was withdrawn and the primitive watermarking was obtained after the anti-Arnold transformation. This algorithm chose the appropriate position to embed the watermarking. Experimental results indicate that the algorithm not only enables the watermarking to have the very good invisibility, but also makes the watermarking have very strong robustness to the general image attacks, such as noise, filter, rotation, compression and so on.