Abstract: To use the non-linear GaAs photoconductive semiconductor switch (PCSS) with avalanche effect for terahertz generation, it is important to quench the photo-activated carrier domain (PACD) transporting in the semiconductor. In this work, a basic setup for quenching the non-linear GaAs PCSS was proposed which consists of two laser beams. The second laser beam was delayed about 100 ps for quenching the PACD after the first beam. In the experiments, the PCSS with 12 mm electrode gap can be biased up to 32 kV with 0.9 kA switching current. Good reproducibility of waveforms about 230 times at 20 kV is achieved with 14mm PCSS when trigger laser is orders of magnitude of tens milli-joules. Results show the process of infrared quenching non-linear mode could be operating repeatedly, which paves the way for future research of high power terahertz generation at high repetition rate.