The simultaneous imaging polarimeter is a type of polarimetric remote sensors with high spatial resolution based on a large aperture off-axis three-mirror system, and the system adopts simultaneous polarimetric measurement based on the prism to divided amplitude. As the instrument has many polarizers and their characteristics are complex, the measurement matrix of instrument deviates from the ideal value. In order to ensure the polarization measurement accuracy of the instrument, we need an effective polarization calibration method. In this paper, a calibration method using the standard liner polarization light source and circular polarization light source is proposed for amplitude-divided simultaneous imaging polarimeter. The linear polarization calibration source calibrates the first three columns of the instrument measurement matrix. The calibration coefficients are obtained by the least-squares fitting Fourier coefficient. The circular polarization calibration source calibrates the fourth column of the instrument measurement matrix. To eliminate non-ideality of the circular polarization state of the light source, two measurements with light source rotated 90°are averaged. Finally, the polarization measurement accuracy of the simultaneous imaging polarimeter is verified by the test. The results show that the polarization measurement accuracy after calibration is better than 1%(P≤0.3).