Potassium-doped tungsten (W-K) and pure tungsten samples were fabricated by the spark plasma sintering (SPS) method and irradiated by He plasma. The samples were characterized by relative density, optical microscopy, and atomic force microscope (AFM) and scanning electron microscope (SEM) measurements. Through tuning the sintering parameters, samples with different K content but similar density and size distribution were obtained in this study. It is found that a sample with higher K content shows better resistance to helium irradiation than that containing less K. In addition, both W-K samples show better performance than pure W in low energy He resistance, indicating that the potassium doping is helpful for improving He-plasma-irradiation resistance for tungsten-based materials.