Abstract: In control system design some parameters must be chose optimistically.Generally,“optimization”is described by maximum or minimum of target function.Quite a lot well done algorithms can be found in literatures,for example,simplex method. If the criteria of optimum are represtened by some figures of a pucture,the goodness of the pucture will correspond to the value of target function,therefore it can still be solved by simplex method.From the numerical example it is shown that this method is applicable.