The invention relates to a polyvinyl chloride mother liquor resin recovery device. The recovery device comprises an outer shell and an inner shell which are sheathed together. An interlayer is formed between the outer shell and the inner shell. The upper part of the outer shell is provided with a mother liquor outlet; and the lower part of the outer shell is provided with a reclaimed material outlet. The upper part of the inner shell is provided with a mother liquor inlet. The polyvinyl chloride mother liquor enters into the inner shell from the mother liquor inlet. The resin in the mother liquor is subsided on the lower part of the inner shell. As the lower part of the inner shell is communicated with the lower part of the outer shell, the subsided resin enters into a second cone which is arranged on the lower part of the outer shell and enters into a line production system from the reclaimed material outlet on the second cone; therefore, the on-line recovery of the polyvinyl chloride mother liquor resin is realized and the property of the recovered resin does not change. The separated mother liquor moves upward along the interlayer between the outer shell and the inner shell and outflows from the mother liquor outlet arranged on a first cone. The device has high recovery rate; a new power device does not need to be added in the whole recovery process; therefore, the recovery cost is not added.