In order to realize the synchronous secure encryption of two plains, a double image encryption algorithm based on the combination of discrete multi-parameters fractional angle transform and low dimension mapping is proposed. The composite coefficient matrix model is constructed based on discrete cosine transform (DCT) and Zigzag scanning, and the two plains are merged into an image by using inverse discrete cosine transform (IDCT). The initial condition values are calculated by using mean value of the plain pixel and external key with the coupled Logistic mapping, and two random sequences are outputted by iterating this coupling map. The position array disrupt mechanism is constructed by sorting two random sequences for scrambling compound plain. The scrambling cipher is decomposed into two new components, and the two new components are fused into temporary cipher by combining the chaotic random phase mask generated by logistic map with modulated phase mask. A new 2D multi-parameter fractional angle transform is constructedbased on discrete fractional angle transform. The encryption model is designed and image encryption is completed. Results show that the proposed algorithm is more secure than the existing dual image encryption schemes, and has better anti-plaintext attack characteristics.