The centralized PI controller based on the equivalent transfer function(ETF) for high dimensional multivariable non-square systems with delays is investigated. By exploiting the relationship between the ETF and Moore-Penrose pseudo inverse of the transfer function of the non-square systems, a higher accuracy analytical expression of the ETF is derived. The proposed ETF design approach not only avoids the complexities of pseudo inverse matrix, the improves the control performance, but also can be applicable to high dimensional non-square systems. Several examples are employed to illustrate the effectiveness and the advantages of the designed method over others.