An image encryption and hiding technique based on composite chaos and LSB is proposed, this method firstly uses Logistic mapping and Tent mapping to be composited to produce chaos mapping, the parameters of the composited chaos are controlled by grey-level information of plain color image, then the produced chaos sequence encrypts the color image, and then the encrypted image is embedded into two or multiple carry images to be transmitted by LSB algorithm. Experiment and simulation results indicate that this method has the feature of good hiding effect, strong encryption-decryption sensitivity and high robustness.