The high-level quantum chemistry ab initio multi-reference configuration interaction method (MRCI) with reasonable aug-cc-p VQZ basis sets is used to calculate the potential energy curves of 5 -S states of BS+ radical related to the dissociation limit B+(1Sg)+S(3Pg) and B+(1Sg)+S(1D), where the ground state of X3 is determined. The spin-orbit interaction is firstly considered, which makes the calculated 5 -S states split in to 9 states. Calculated results show that avoided crossing rule exists between the states of the same symmetry. Analysis of electronic structures of -S states shows that the -S electronic states are multi-configuration in nature. Then the spectroscopic constants of the bound -S and states are obtained by solving the radial Schrdinger equation. All of these data will provide accurate information of the electron structure for further research on BS+ in theory and experiment.