Provided are a physiological signal sensing system and a physiological signal sensing method. The physiological signal sensing system includes a physiological signal sensing apparatus, a variation sensing apparatus, and a signal processing apparatus. The physiological signal sensing apparatus is disposed on a fabric to sense and provide physiological signals of an organism. The physiological signal sensing apparatus includes capacitive coupling devices. The variation sensing apparatus is disposed on the fabric and includes a distance sensing device to sense a distance between the physiological signal sensing apparatus and the organism, and provide a first capacitance variation signal according to the distance. The signal processing apparatus is coupled to the physiological signal sensing apparatus and the variation sensing apparatus to receive the physiological signals and the first capacitance variation signal and correct the physiological signals according to the first capacitance variation signal to obtain corrected physiological signals.