The invention relates to a wireless real-time monitoring system of an in-transit nitrogen pressure in a large transformer, which belongs to the technical field of conveyance monitor of the large transformer and solves the technical problem of providing a device capable of accurately and wirelessly monitoring the in-transit nitrogen pressure in the large transformer for a long time. The system is characterized by comprising an integrated controller installed at the cab of the transport vehicle of the large transformer, a router installed at the top end of the large transformer and a wireless real-time monitoring device of nitrogen pressure installed at the upper part of the tail of the transport vehicle of the large transformer, wherein the integrated controller, the router and the wireless real-time monitoring device of nitrogen pressure are all in wireless network communication; the integrated controller stores information sent by the router and the wireless real-time monitoring device of nitrogen pressure; and the wireless real-time monitoring device of nitrogen pressure comprises a nitrogen pressure sensor for collecting nitrogen pressure. The wireless real-time monitoring system is suitable for the field of the transportation of large transformers.