In order to acquire the full Stokes parameters in the new hyper-spectropolarimetric imaging system quickly and accurately, which is filtered by the acousto-optic tunable filter (AOTF) and modulated by the liquid crystal variable retarder (LCVR), we propose a new measurement method that two LCVRs are controlled by one driving signal source, and we take four fixed driving voltages in turn when the LCVR phase modulation is carried out under different wavelengths. The full Stokes parameters about incident light via the corresponding mathematical calculation are obtained. In order to verify the accuracy of this method, we take three polaroids with the polarization directions of 0°, 90°, and 45° respectively and a quarter-wave plate as the target, with a sheet of frosted glass as the background. Images of all the Stokes parameters are obtained by the imaging system. The results show that the proposed method can obtain all Stokes parameters with high imaging quality. In addition, we further verify the feasibility of the system and the accuracy of the method with the aid of hyper-spectropolarimetric imaging of true leaves and false leaves with different colors. The factors that influence the measurement accuracy of Stokes parameters are analyzed theoretically, providing a theoretical basis for further improving measurement accuracy.