Inspired from the clonal selection mechanism of immune systems and the theory of the cloud model, a chaos clonal selection algorithm based on cloud model was proposed to improve the algorithm. Firstly, the algorithm adopts chaos initialization to generate the initial population in order to improve the quality of initial antibodies. Secondly, the algorithm employs the basic normal cloud generator to achieve antibodies mutation operation in order to improve the diversity of antibodies. Finally, the simulation test of classical function and the parameters tuning of time-delay system with active-disturbance-rejection controller shows that the algorithm can search for the best solution more quickly. Its precision is higher and its stability is better than the CSA, GA and PSO.