Abstract: Aimed at a reiterative free network,this paper puts forward the conception of the displacement weight R and the principle of the solution to the rank-defect normal equations according to the fact that the weighted norms of unknown vectors are the least.In this paper are included:the deductions of the equations,analysis of their methods and examples,and a few examples in computer calculations.Although this paper deals only with the plane control network,the method that the paper puts forward may also be used to adjust other types of free network.