A novel refractive index sensor based on one-dimensional photonic crystal non-complete surface defect is introduced and the principle and the method of the sensor are discussed. The experiment system used to detect the refractive index was constructed to get high resolution and high Q-value. The sensor is verified by detecting the dimethyl sulphone solution. The experimental result indicates that this refractive index sensor’s sensitivity is 3 025 nm·RIU-1, and when the resolution of spectrometer is 0.01 nm the resolution of this sensor is 3.3×10-6 RIU. The Q value of this sensor is 260, and the sensor has good linearity in 1.4～1.42 range (the linearity is 0.991 27). It was analyzed how the photonic crystal periodicity and liquid thickness affect the Q value of the sensor. The result proved that this kind of total reflection photonic crystal surface wave sensor is label free, which is similar with SPR sensor, and the sensor has high resolution, high Q-value and has real-time survey characteristic.