The invention belongs to the field of blow molding, and particularly relates to a device for an automotive oil tank blowing mold. The device comprises a base, a vertical plate, a transverse plate, a trapezoidal guide groove, a part taking mechanism and a receiving mechanism. The vertical plate is installed on the base, and the transverse plate is installed on the side face of the upper end of thevertical plate. According to the device, in the process that a clamping ring insert is moved towards the position where the clamping ring insert is clamped in advance in the blowing mold, a control system controls a power unit A, a power unit B and a power unit C to carry out the operation in the whole process, placement of the clamping ring insert at the position where the clamping ring insert isclamped in advance in the blowing mold is accomplished, and automatic reset is conducted after blow molding is finished. The phenomenon that due to the fact that the clamping ring insert is manuallyplaced at the position where the clamping ring insert is clamped in advance in the blowing mold, an injury accident happens is fundamentally avoided. In addition, the labor amount of a worker in the blow molding working procedure is reduced, the working efficiency is improved, and the human cost is also reduced to a certain extent.