The segmented primary mirror is employed to construct the next-generation ground- and space-based large telescopes. Because of many disturbances, the segmented mirrors within the segmented primary mirror easily deviate from the desired position, leading to rigid misalignment. In particular, the piston error of segmented mirror along the direction of local optical axis and the tip/tilt error seriously affect the imaging quality. The statistical properties of the misaligned discontinuous wavefront caused by piston and tip/tilt errors and the centroid of the image field of the misaligned segmented optical system are analytically evaluated from a statistical perspective. Further, the Strehl ratio is calculated based on the Maréchal approximation by combining the statistical properties from the random discontinuous wavefront. The results of this study can be used to improve the understanding of the performance of the segmented imaging system.