The input to the power system stabilizer（PSS） consists of two signals， local signal and global signal respectively， which forms two-level PSS control. Local signal is local generator rotor speed while two global signals are suggested as the tie-line active power and inter-area speed difference signals. The phasor of global feedback is stable. Global measurement signal is selected according to participation factor and residue of transfer function and PSS is configured by mode analysis. Simulations on two-area four-machine power system demonstrate the advantage of two-level PSS control in enhancing power angle stability and transfer capability.