The invention discloses a welding device. A welding mechanism is fixed to a support. A turnover position-changing mechanism comprises a rotation frame, a first rotation piece, a first drive piece andtwo workpiece fixing structures. The first drive piece is fixedly connected with the first rotation piece and drives the first rotation piece to rotate along a first axis relative to the welding mechanism. The rotation frame comprises two second rotation mechanisms. Each second rotation mechanism comprises a second drive piece and a second rotation piece. The second drive pieces are fixedly connected with the second rotation pieces and drive the second rotation pieces to rotate along a second axis relative to the welding mechanism. Each workpiece fixing structure comprises a third rotation mechanism. Each third rotation mechanism comprises a third drive piece and a third rotation piece. The third drive pieces are fixedly connected with the third rotation pieces and drive the third rotationpieces to rotate along a third axis relative to the welding mechanism. A workpiece is fixed to the turnover position-changing mechanism. The turnover position-changing mechanism drives the workpieceto rotate in multiple directions. Workpiece position regulation is more convenient and accurate.