Based on the isospin quantum molecular dynamics (IQMD) transport theory model, the initialization of intermediate energy heavy ion collisions was studied. The non-physical fluctuation and the emission of virtual particles in the collision process can be reduced by successful initialization, which is conducive to the stability of the next two-body collision. Different symmetry potentials have certain influence on the stability of nuclei. Fe, Kr, Sn and their isotopes with different mass numbers were selected, and the stability of nuclei was verified by the evolution with time in their own mean field. The number of stable nuclei was initialized statistically, and the most stable symmetry potential was selected. The study shows that the symmetry potential U₂ of the square term is the most stable, and its corresponding slope L and incompressible coefficient K_sym are all within the known constraint range. When the isospin dependent mean field takes the hard potential, the nucleus is more stable.