The invention discloses an inserting-type sand blasting nozzle used for hot box flexible installation. The inserting-type sand blasting nozzle comprises a hot box sand blasting nozzle installation welding block (6), a sand blasting plate (1) which is welded with the welding block, a sand blasting nozzle cap (3), a sealing ring (4) and a sand stopping block (5). The inserting-type sand blasting nozzle is characterized in that the upper portion of a sand blasting nozzle body (2) is provided with a flange plate or an unthreaded rod, and the lower portion of the hot box sand blasting nozzle installation welding block (6) is provided with a groove matched with the flange plate or the unthreaded rod on the upper portion of the sand blasting nozzle body; the inner diameter of the groove is larger than that of the flange plate or the unthreaded rod by 1-2mm; and the sand blasting nozzle body, the welding block and the sand blasting plate are fixedly connected into a whole at the outer side of the groove through a screw (7) and a sand blasting nozzle limiting ring (8). By means of the inserting-type sand blasting nozzle used for hot box flexible installation, core-making efficiency of a hot box is improved, and by the adoption of a standard component connecting mode, the structure is simple and deflection is small; on one hand, the problems that an inserting-type sand blasting nozzle is prone to deformation and short in service life are solved; and on the other hand, the defects that the existing inserting-type sand blasting nozzle is large in using quantity of materials, high in installation structure manufacturing difficulty and low in efficiency are overcome.