The utility model discloses a welding positioner. The utility model relates to an overturning device, which comprises a machine frame, a revolving platform, a support platform, an overturning drivingdevice and a revolving driving device, the support platform is connected with the machine frame, the overturning driving device comprises a first motor, a first speed reducer connected with the firstmotor and an overturning gear connected with the first speed reducer, and the overturning gear is connected with the support platform through an overturning shaft. The rotation driving device comprises a second motor, a second speed reducer connected with the second motor and a rotation gear set. The rotation driving device of the welding positioner can achieve rotation of the rotary table, and the turnover driving device can achieve turnover of the rotary table and the supporting table. Two-stage speed reduction is achieved through the first gear shaft and the second gear shaft of the rotarydriving device, the rotary table can rotate forwards and backwards, stepless speed change can be achieved, the speed regulation precision is high, and the rotary table is suitable for welding of various pipeline pieces, shafts, discs and other complex structures.