A positioning device used for accurately manufacturing a complex automobile accessory. The positioning device comprises a platform, a base is arranged on the platform, a fixing plate used for limiting Y-axis direction of one end of the accessory is arranged on the base, a retaining plate used for limiting Z-axis direction of one end of the accessory is arranged on the fixing plate, a lateral retaining plate used for limiting X-axis direction of the accessory is arranged on the base, and a limiting part used for limiting Z-axis direction of one end of one side, opposite to the retaining plate, on the accessory is arranged on the base. Through a separated positioning mode, positioning structure is simplified, operation steps are reduced, more convenience in replacement of the automobile accessory is realized, and the positioning device is suitable for large-scale
welding operation. In addition, the whole positioning device is simple in structure, firm in positioning and high in accuracy.