The method of B3LYP/ 6-311G (d) in density functional theory (DFT) was used to optimize the geometric configuration and study the photoelectron energy spectroscopy of Sin-1N and Sin-2N2 (n=3～8) ion clusters, and the results were found as follows: first, the ground-state structures of the clusters were obtained, and the symmetry of Sin-2N2 (n=3～8) ion clusters was better than Sin-1N (n=3～8). Second, there was a transition from planar to spacial structures at n=4 and n=6. For Sin-1N (n=3～8), the structure was planar when n≤4, and the other was spacial structure. For Sin-2N (n=3～8), the structure was planar with n=6, and the other was spacial structure. Finally, the structure with even n was more stable than those with odd n in Sin-1N+ (n=3～8) clusters; the structure with odd n was more stable than those with even n in Sin-1N-, Sin-2N-2 and Sin-2N+2 (n=3～8) clusters.