Provided is a substation electric energy acquisition multiplexing test system. The substation electric energy acquisition multiplexing test system is capable of distributing cables when a switch cabinet is operating, and carrying out communication test for an ammeter synchronously and directly. The substation electric energy acquisition multiplexing test system includes a collinear multiplexing module, a selection switching module, and a field interface on-site test module. In the substation electric energy acquisition multiplexing test system, the collinear multiplexing module, the selection switching module, and the field interface on-site test module are integrated, and acquisition for electric energy of ammeters of different specifications is achieved through one RS485 bus, so that no repeat wiring is needed, the difficult of wiring construction is solved, direct testing for the ammeter by a PC is achieved through providing a USB interface, field testing level of an acquisition system is improved, workload and work time are reduced, and work efficiency is improved. With the substation electric energy acquisition multiplexing test system, maintenance work of an electric energy acquisition system of a substation is facilitated greatly, and actual difficulties in work are solved.