PSS4B is a new type of multi-band power system stabilizer. Due to the characteristic in suppressing several oscillation modes simultaneously and its more flexible settings, PSS4B has broad application prospects. Because the parameter setting for PSS4B becomes more complex, related research is less still. From the practice requirement, with multiply system operating conditions considered in this paper, the phase compensation approach is used to determine lead/lag time constants, and the root locus method is applied to confirm gains. Based on the probabilistic eigenvalue analysis, parameters of PSS4B are determined by probabilistic sensitivity analysis, while considering the influences among PSSs have been partly considered. Analysis on an eight-machine system shows that the equipped six PSS4Bs can provide effective damping for concerned oscillation modes.