Based on the structural feature of helix drilling joint, the combined extrusion for solid billet and open-die backward extrusion for hollow billet were designed. By the help of elastic-plastic finite-element analysis software, the forming process was simulated. The upsetting collapse was analyzed in the scheme of open-die backward extrusion for hollow billet and a solution plan was put forward. The solution plan was put forward that boot area was set at the front-end of the male mould land. At last, the forming forces were compared, and the force of open-die inverted extrusion for hollow billet was 87.3%  smaller than combined extrusion for solid billet. The experiment results show that open-die inverted extrusion for hollow billet could be extruded to qualified extruding part.