The invention discloses a signal switching matrix, comprising a plurality of splitters which are mutually in electric connection to form a net structure; the plurality of splitters are provided with coupling ports switching signals with the outside. The splitters are provided with a plurality of branches which are all in tandem connection with other splitters, and then the plurality of branches of the splitters are in tandem connection with splitters, thereby infinitely expanding in such a mode to form a net shape; each branch of a splitter is a channel for transmitting signals, and each splitter is provided with a port switching signals with the outside, thereby meeting test requirements of a multi-line network/ relay.