A novel laser chaotic coding system was studied herein. The proposed system realized the application of cross emission and alternate parallel reception (CEAPR) in chaotic secure communications using two space-coupled lasers synchronizing with two other lasers. We theoretically determined two chaotic coding and decoding equations of the CEAPR. In addition, the mathematical physical principle of CEAPR coding and decoding of chaotic laser was defined and described. Two practical applications of the CEAPR technology were developed herein. The proposed system characterizes different parameters between the emitter laser emitting chaotic coding carrier and the receiver laser, which is different from the traditional chaotic communication system that has the same parameter secret-keys for the emitter and receiver. The emitters have multiple-parameters and multiple-variables, can implement alternating transmission of information security, and has a flexible application. It makes it difficult for invaders to decipher the communication contents from the carrier.