The present invention relates to the field of communications technologies, and discloses a combined phase shifter and a multi-band antenna network system. The combined phase shifter includes at least two laminated phase shifters, and different phase shifters have different frequency bands. Each phase shifter includes a signal layer and components that are slidable relative to the signal layer and that are configured to change a phase of an output port of the signal layer. A filter circuit is provided at the output port of the signal layer. Output ports of filter circuits corresponding to the at least two phase shifters are connected by using a conductor, and perform output by using a common output port. In the technical solutions of the present invention, output ports of two phase shifters having different frequencies are integrated by using a conductor to perform output. In comparison with the prior art, a quantity of cables used in a multi-band antenna network system is reduced. This facilitates a layout, thereby making it convenient to dispose the multi-band antenna network system. In addition, this facilitates a layout of an entire machine, reduces a weight of the entire machine, and reduces costs. In addition, the combined phase shifter provided in this embodiment of the present invention may also increase antenna gain, and optimize pattern parameters.