The chaotic encryption system which makes use of chaos mapping system to carry on the secret correspondence is introduced. The method which makes use of the chaos dynamics equation to carry on encrypting to pictures is put forward and realized with the program. For the one-dimension chaotic encryption method, it is successfully deciphered by the phase-space reconstruction theory and exhaustive method with the encryption function, parameter and the original value completely unknown. In the end, the advantages and the disadvantages of the encrypting and deciphering methods are discussed and a kind of encrypting project which is more difficult to be deciphered is put forward.