Sensitive and reliable hydrogen detection at ultralow concentrations is essential for hydrogen safety as well as hydrogen related materials research. In this work, a hydrogen sensor based on palladium nanoparticles (PdNPs) functionalized single-walled carbon nanotubes (SWCNTs) is fabricated using a facile deposition process and evaluated under controlled hydrogen sensing conditions. The sensor chip consists of 16 sensing channels and enables systematic comparison of different deposition parameters. The sensing performance at room temperature is investigated at hydrogen concentrations ranging from 200 to 500 ppb. The PdNPs functionalized SWCNTs sensors exhibit clearly distinguishable and reproducible responses down to 200 ppb. Based on the signal to noise ratio (SNR), a theoretical detection limit of 10.77 ppb is determined, and a linear concentration to response behavior is maintained. In addition, stable sensor responses are demonstrated under repeated exposure cycles and prolonged hydrogen exposure, indicating the robustness of multiparameters PdNPs functionalized SWCNTs sensors for ultra-low concentration hydrogen detection at room temperature.