Abstract: In optical engineering application, the prisms′ beam folding function is often used to implement the image rotation, detection and measurement. In this paper, considering the effect of the machining error of prisms on the optical axes in the engineering application, the matrix, characteristic direction and extreme-value axial direction of the right-angle roof prism and corner-cube prism were obtained with the dynamic optical theory and the derivation formula. Thus, the mathematic models of optical axes of the two prisms were derived. According to the actual machining error, the theoretical error sources of the two prisms were deduced, and the comparative analysis for both prisms was conducted. Finally, it is concluded that the right-angled roof prism should be used instead of the corner-cube prism.