The utility model discloses a general basis of main transformer, including buttress and raft board. The buttress is the precast reinforced concrete piece, the below is pre -buried to have a pre -buried steel sheet, offer the installation of chemical bolt on the pre -buried steel sheet four corners and use the connecting hole, the raft board adopts the reinforced concrete scene and casts, transversely set up two rows of chemical bolt installations on the raft board and use predrilled holes, two rows of predrilled holes are according to the horizontal center line symmetry of raft board, the predrilled holes horizontal spacing is 50mm, the longitudinal separation is the same with the longitudinal separation of connecting hole with the chemical bolt installation on the pre -buried steel sheet, buttress quantity is 2, according to raft board longitudinal center line symmetric placement on the raft board, its vertical center distance is the gauge, insert chemical bolt through pre -buried steel joining of plates hole the predrilled holes of raft board, connect buttress and raft board. The utility model discloses simple structure, buttress and raft board can be made respectively during the construction, have practiced thrift the engineering time, can be used to mate the multiple specification transformer of installation.