The purpose of the present invention is to provide a control device for a dynamometer system, with which, by a simple method, an unloaded state can be reproduced highly accurately when a test piece is started. A dynamo control device 6 is provided with: an integral control input computation unit 611 for computing the integral value of axle torque deviation, and multiplying the sum thereof and a correction value by an integral gain to compute an integral control input; a correction value computation unit 612 for multiplying an inertia compensation quantity Jcmp by the dynamo rotation frequency to compute a correction value; a non-integral control input computation unit 613 for designating, as a non-integral control input, the output of a prescribed transmission function Ge0(s) having axle torque deviation as input; and a totaling unit 614 for totaling the integral control input and the non-integral control input in order to generate a torque current command signal to the dynamometer. The transmission function Ge0(s) of the non-integral control input computation unit 613 is derived by separating the integrator from a transmission function Ge(s) having an axle torque control function, in such a way as to satisfy the relational equation (Ge(s)=Ki/s+Ge0(s)).