[en] Muon tomography, as a novel method of radiography, utilizes the multiple Coulomb scattering property of muons from cosmic rays to discriminate materials. Researchers around the world have been developing various detection systems and image reconstruction algorithms for muon tomography applications, such as in the fields of nuclear reactor monitoring and cargo inspection for contrabands. This paper studies the principle of image reconstruction in muon tomography. The implementation and comparison of some popular algorithms with our simulation dataset are presented, together with ideas regarding potential improvements in image quality and material discrimination performance.