The invention relates steel tube automatic baiting unit. The unit comprises moving mould, plunger tip, static model, feeding, transmitting part and operating board. The static model is fixed on the operating board, moving mould is on the guide rail of operating board, the plunger tip is above moving mould, and feeding part is on the end of operating board. The transmitting element of transmitting part is connected with the end of the bent axle of sources of power presser, and the output shaft of transmitting part is connected with feeding part. The static model comprises static model body, static molding, and floating core. The moving mould comprises moving mould body, movable mould part, moving molding, moving core, moving chock, static chock and elastic body. Using the unit, the product can't deform, the cross-section planeness is high, and the productivity is improved. The unit is used to product many kinds of steel tubes whose wall thickness is 2-15mm.