The application discloses a combined phase shifter and a multi-band antenna network system. The combined phase shifter includes at least two phase shifters. The phase shifters have different frequency bands. Each phase shifter includes a signal line layer and components that are configured to change a phase of an output port of the signal line layer. The components are slidable relative to the signal layer. A filter circuit is provided at an output port of the signal layer. Output ports of filter circuits corresponding to the at least two phase shifters are connected by a conductor, and perform output using a common output port.