The present invention relates to a control device design method for a control device that determines a manipulation amount of a control object having a dead time by feedback control so as to bring a control amount of the control object closer to a target value. The method according to the present invention includes a step of designing a feedback loop that computes a correction amount for the manipulation amount using a plurality of controllers including a prediction model of the control object, a step of deriving the same number of delay elements as the plurality of controllers from a dead time element of the prediction model, and a step of allocating the plurality of controllers associated with the delay elements to a plurality of arithmetic units so that the computation of the feedback loop is performed by parallel computation by the plurality of arithmetic units that operate in parallel.