The invention discloses a transformer junction box, comprising a transformer secondary junction box and a state conversion module, wherein at least one first circular connecting hole is formed in therear end of the transformer secondary junction box, and the transformer secondary junction box is connected with a transformer body secondary outlet box through the first circular connecting holes; atleast one second circular connecting hole is also formed in the front end of the transformer secondary junction box, and the transformer secondary junction box is connected with external working equipment through the second circular connecting holes; at least one first groove is also formed in the upper end of the transformer secondary junction box, and the transformer secondary junction box is connected with a first metal connecting component at the lower end of the state conversion module through the first groove; and the state conversion module can slide in the first groove. The scheme ofthe invention has the following beneficial effects: a transformer-to-secondary power equipment wiring function can be realized, a transformer detection and debugging wiring function can also be provided, the test wiring can be facilitated, and the production efficiency can be improved.