<p>Based on the improvement of image transmission security and turbulence resistance in FSOC transmission, this paper proposes a color image FSOC transmission scheme based on a hyperchaotic image encryption system. Firstly, the scheme constructs a hyperchaotic system by combining small perturbations with state variables, and uses phase diagrams, Lyapunov index diagrams, and path entropy to show the complexity and anti-interference of the system. Secondly, based on the improved hyperchaotic system, a chaotic image encryption system is designed by using chaotic mapping combined with DNA coding technology. The security and robustness of the chaotic image encryption system are tested in detail using simulation test experiments. Finally, based on the combination of Log-normal and Gamma–Gamma turbulence models with chaotic image encryption system, color images of different sizes are used to test under channel conditions of different turbulence intensities, and the transmission image effects are compared and analyzed. The results show that under different turbulence intensities, the scheme has good turbulence resistance characteristics. And the image pixel changes are compared by comparing the NPCR value and UACI value, which further verifies the superiority of the design scheme.</p>