In recent years,search mapping carrier free information hiding is very popular.Al though it has certain robustness,it has low hiding capacity,large transmission load and high algorithm complexity.To solve the above problems,this paper proposes a carrier free inform ation hiding method based on Arnold scrambling and discrete cosine transform (DCT) coding.The algorithm first completes Arnold scrambling of the pictures,then encodes the low-frequency coefficients afte r DCT,and then changes the scrambling parameters to build the index table.The algorithm selects the parameter s corresponding to the same coding value as the secret information in the index table to build a ca ndidate queue,and finally filters out the parameters with strong robustness and send them to the re ceiver as a key. Experimental results show that compared with the existing methods,this method g reatly improves the embedding capacity and has stronger anti JPEG compression performance.The algor ithm reduces transmission load,is simple and has strong application value.