Based on the density functional theory, using full-potential linearized augmented plane wave and improved local orbital and GGA method, the structures, energies, magnetism, electronic bands, and densities of states of the superconductivity 122 type AeT2Pn2 compounds were calculated and analyzed. The superconducting transition temperature (TC) of AeT2Pn2 was analyzed with the bond lengths, bond angles, magnetism, electronic bands, and densities of states.The favorable factors to heighten TC for 122-type Fe-based superconductor was given.The results showed that ［Fe2As2］ black series have the strongest spin-polarized magnetism, most stable antiferromagnetic structure, obvious splitting of spin-up and down bands at Fermi level, and canonical tetrahedral FeAs4, and the TC relatively higher than ［Ni2As2］and［Fe2P2］ series.