Numerical analysis of a large-scale finite periodic array is accurate but quite costly when the array is analyzed as a finite array. The computational cost for the numerical analysis can be reduced greatly when the array is approximated as an infinite periodic structure. However, the edge effect that strongly affects the active impedance or current distribution of the array elements near the edge is neglected. In this paper, a macro block-characteristic basis function method (MB-CBFM) for numerical analysis of a large-scale finite periodic array with a uniform amplitude and linear phased excitation is proposed. The MB-CBFM utilizes blocks and macro blocks to group the elements in order to reduce its computational cost without degrading accuracy. Numerical simulations demonstrate that the CPU time and computer memory of the MB-CBFM are O(N) when the size of array is sufficiently large.