Multi-frequency mixer

The utility model relates to a multi-frequency mixer comprising a first input port which is used for inputting a first frequency band signal, at least one second input port which is used for inputting a second frequency band signal, and an output port; the first input port is electrically connected with the output port through an LC filter circuit; and the second input port is electrically connected with the output port through a cavity filter. According to the multi-frequency mixer, the filtration to the first frequency band signal is realized through the LC filter circuit, a plurality of second input ports are integrated, so that the multi-frequency mixer has the characteristics of simple structure, low cost and easiness in processing and production, and the mixing of wider bandwidth can be realized.