In this paper,we study the cooperative output regulation problem for a class of general linear uncertain multi-input multi-output (MIMO) multi-agent systems subject to a well-defined vector relative degree.By proposing some suitable inteal model,the problem is first converted into the auxiliary cooperative stabilization problem of the augmented system in the so-called strict feedback normal form.This auxiliary problem is then solved by some developed robust control techniques,such as multiple high-gain feedback and mixed distributed observer,leading to an effective distributed output feedback regulator synthesis for the original cooperative output regulation problem.