The invention discloses a multisource input telecontrol transmission method for fusing automation information of different manufacturers of a transformer substation, especially for performing continuous transmission on information when new automation equipment and old automation equipment coexist during modification of the transformer substation. Two serial communication modules are respectively connected with a new system data interface and a raw old system data interface in a grid to respectively acquire new system data and raw old system data in the grid, and the acquired data comprises analog quantity data and state quantity data; validity analysis is performed on the state quantity data of a new system and the state quantity data of an old system by contrasting validity data in a scope database, and the data belonging to the validity data is got out and stored into a valid database, and data in recent time period in the valid database is called and is uploaded to a monitoring center through an internet access communication module. According to the multisource input telecontrol transmission method disclosed by the invention, the new data and the old data cannot lose, and steady transformation is realized; meanwhile, the problem that new telecontrol equipment and old telecontrol equipment cannot be connected with a superior dispatching system simultaneously is solved.