The utility model provides an interface device between railway STP system and LTE network, including the on -vehicle host computer that connects gradually, pass module, EPC, DSC server and station host computer thoroughly, the module that passes thoroughly for RTM and CPE composite set, specifically include the serial ports controlling means and the LTE module controlling means that connect through communication control device, wherein serial ports controlling means is connected with on -vehicle host computer through serial protocol interface, communication control device agrees serial protocol conversion one -tenth TCPIP, LTE module controlling means inserts the LTE network to mode through TCPIP is communicated in EPC. The utility model discloses use LTE network replacement GSMR network,the complete set is IPization all, and on -vehicle host computer is establish the process with the safety chain between the host computer of station and is simplified into two sections, has strengthened system reliability.