Aiming at the problem of poor robustness of image watermarking algorithms when t he attack is strong,a robust method based on graph-based transform (GBT),discret e wavelet transform (DWT) and singular value decomposition (SVD) is proposed.First,we perform non- overlapping block processing on the carrier image,select the sub-blocks with higher pixel varian ce values and perform DWT on each sub-block to obtain its low-frequency coefficient matrix,and then perform GBT and SVD on the low frequency coefficient matrix in turn to obtain the singular value matrix,and fi nally embed the watermark information to the largest singular value matrix.The experimental res ults show that when Pirate image structure similarity (SSIM) reaches 0.97 or more,the algorithm in this pa per can effectively resist attacks such as noise,filtering,JPEG compression,cropping,and exchang e of ranks,and the normalization coefficient (NC) value is all above 0.9.