This paper deals with the design of dead-beat control with optimal robustness for multivariable systems. First, a necessary and sufficient condition for the existence of stabilizing dead-beat controllers is derived based on the YJB parametrization of all stabilizing controllers. Then, a robustness index is proposed that is optimized under the constraint of internal stability. The bound of robustness improvement is also shown by calculating the limit value of the robustness index. Finally, numerical examples are given to illustrate the theoretical results.