Hydrogen resource can be saved by reuse and purification reuse between refineries. Thus, it’s necessary to optimize the inter-plant hydrogen network in a petrochemical complex. In a petrochemical complex, purifiers are employed to recover hydrogen components from off gas. However, purifier models such as PSA, membrane units have non-linear characteristics. Even if minimizing hydrogen utility, mathematical programming models adopted by most of the researchers belong to the non-convex and non-linear models, not guaranteeing global optimal solution. In this paper, a novel mathematic programming model for the optimization of inter-plant hydrogen network with purification unit is presented. If only the hydrogen utility consumption is minimized, the model is linear, guaranteeing global optimal solution. If the object comes to economic benefits such as pipeline cost, the objective function is nonlinear. The hydrogen utilities in refinery can be reduced by the inter-plant optimization and the number of inter-plant connections can be optimized to minimum. Case study indicates that the model is effective.