Muon scattering tomography technology can be of great use in detecting nuclear materials under excellent shielding, thus distinguishing itself from traditional radiography technology. In this study, we firstly introduced the principle of this radiography technology and the rationale of PoCA algorithm used in image reconstruction. Then several experimental models were constructed with the help of Geant4 toolkit, and several sets of simulation experiments were carried out to test the performance of this technology with PoCA algorithm. In order to improve the imaging quality, we designed experiments to find out the cause of distorted image, and then proposed an optimization method. Finally, a quantity was created to present the imaging quality, and several experiments were carried out to validate the effect of this optimization method. The result showed that this method can significantly improve the performance of this algorithm.