The invention discloses a switching network applied to aerospace-grade multi-channel microwave assembly environmental testing and belongs to the testing technical field. The switching network applied to aerospace-grade multi-channel microwave assembly environmental testing includes an environmental test box, an AC/DC power source module and a PCI digital I/O module; a cabinet is arranged in the environmental test box; a microwave switch and module combination is arranged in the cabinet; the microwave switch and module combination comprises a plurality of microwave switches and modules; the panel of the cabinet is provided with a power source connector, a high-density multi-core connector and a microwave connector; the AC/DC power source module is connected with the microwave switches and modules through the power source connector; and the PCI digital I/O module is connected with the microwave switches and modules through the high-density multi-core connector.