Aiming at the contradiction between maximum working distance and detecting accuracy for single-aperture orthogonal coding passive ranging system, a linear array orthogonal wavefront-coding ranging system consisting of multiple ranging sensors was established. The linear array geometry was given. The relation of OTF for array system and single-aperture system was obtained by summing multiple coding images from each sensor. The mathematic expression of optimal array separation for two-sensor array geometry was deduced. The minimum-redundancy linear array geometry can generate the more unique spacing responses and modulation cosine terms. The array response for multiple pair of sensors was obtained. The Cramer-Rao bound of range estimation was analyzed using Fisher information matrix. Theoretical and simulated results show that array ranging system can narrow bandpass region of range-dependent peak in the MTF, and lower minimum variance bound of range estimation, and improve detecting accuracy by double at least, as compared to the single aperture system for a given range.