A novel scheme based on polarization modulators to generate Sub-Terahertz wave (Sub-THz) signal with frequency 32-tupling is proposed. The system consists of two subsystems in cascade, and each subsystem consists of 4 paralleled polarization modulators. In this scheme, by properly controlling two subsystems, an optical signal with optical carrier and ±16th-order optical sidebands is achieved. Next, by adjusting the optical attenuator and optical phase shifter, the optical carrier can be canceled. Finally, the Sub-THz wave with frequency 32-tupling can be obtained after beaten in the photodetector. The results show the ±16th-order optical sideband suppression ratio (OSSR) is derived as 55.7 dB and the radio frequency sideband suppression ratio (RFSSR) of the 32-tupling Sub-THz wave is derived as 43.66 dB, which are consistent with the theoretical analysis very well. Meanwhile, the effects of phase offset, modulation index, and attenuator deviation on suppression ratio are analyzed.