In order to measure the refractive index of liquid accurately, quickly and conveniently without contact, this paper presents a scheme to measure the refractive index of transparent liquid by using refraction method and linear CCD, and designs a new device to measure the refractive index of liquid. The optical path of the device is precisely designed and applied to the measurement of liquid refractive index, and the measurement results are quantitatively analyzed. The relative error of refractive index of ethanol solution with different concentration is less than 0.6%. The device has the advantages of simple structure, good portability, simple operation and accurate measurement, and achieves high precision measurement of refractive index of transparent liquid.