The invention relates to the continuous steel-making production, in particular to a continuous steel furnace siphon slag-free tapping hole, comprising a tapping pipeline, a power supply coil (5) arranged around the tapping pipeline, a smoke outlet (6) arranged on the upper part of the tapping pipeline and a water cooled wall (11) arranged on the outside of the tapping pipeline; the Z-shaped tapping pipeline comprises a slag-free tapping hole inlet (2), a vertical pipeline (3) and a slag-free tapping hole outlet (4), wherein, the slag-free tapping hole inlet (2) is lower than the slag-free tapping hole outlet (4), the slag-free tapping hole inlet (2) has an included angle of 86 to 92 degrees with the vertical pipeline (3) and the slag-free tapping hole outlet (4) has an included angle of 50 to 90 degrees with the vertical pipeline (3). The slag-free tapping hole provided by the invention has the advantages of simple structure, easy maintenance and long service life. In the normal operation, the slag-free tapping hole is heated by the flue gas heat of an oxygen blowing furnace to prevent the molten steel from freezing or felting, thus saving energy.