To remove the influences of system error and electro-optical modulation on the measurement result in the infrared detector S parameter measurement based on a lightwave component analyzer, a calibration method based on 12-term error coefficient is proposed. On the basis of the network modeling of both electro-optical modulation and S parameters of an infrared detector, the DFD of the measurement system is designed. The S parameter correction formula is derived. The S21 parameters of the infrared detector are measured in the range from 10 MHz to 20 GHz. The Pearson Product-moment Correlation Coefficient (PPMCC) between the data obtained by the proposed method and the data measured by using a N4375D-type analyzer is 0.997. The result shows that the data are in good agreement and the validity of the proposed method is verified.