Abstract: The Full-Gauss beam through an axisymmetric periodic-focusing magnetic field was studied, and a simple function feedback controller was proposed based on mechanism of halo formation and strategy of controlling halo-chaos. The multiparticle simulation was performed to control the halo-chaos by the simple function controller. The results show that not only the halo-chaos and its regeneration can be eliminated, but also the Guass distribution of density can be found.