In allusion to the strong coupling problem of the time-delayed multivariable linear system, a novel decoupling compensator is designed based on information fusion estimation. For the multi-input and multi-output (MIMO) system, the decoupling compensators of the main channels and their coupling channels are designed separately. Firstly, the controller is disconnected, the input ends of the decoupling compensators are input the set control signals, and then the desired outputs of the coupling channels are zeros. By fusing the soft constraint information of the desired outputs and the control energy of the coupling channels, the optimal decoupling compensation variables under the quadratic performance index can be obtained. Furthermore, the approximate optimal decoupling compensation variables with easier computation can be obtained, when the infinite preview desired outputs are equivalently treated as one-step preview desired outputs. Simulation results show that the decoupling compensator has advantages of small computation and good decoupling quality.