The passive synthesis of the fractional-order driving-point immittance functions is of great significance for the modeling and design of fractional-order circuits. This paper studies the synthesis of a class of two-element-order fractional immittance functions based on variable substitution. First, the method of realizing the two-variable immittance functions corresponding to this kind of two-element-order fractional immittance functions is established; second, we perform the inverse substitution of variables to realize the two-element-order fractional immittance network; finally, the synthesis program of this kind of two-element-order fractional immittance functions is proposed, and specific examples are given for simulation verification. This synthesis method overcomes the disadvantages of using a multi-port transformer, and is more conducive to network analysis.