Abstract: Based on reviewing the principle,performance and mechanism of the turnaround refracture technology,according to the advantages and disadvantages of the current conventional fracturing and turnaround refracture technology, the similarities and differences of the current conventional fracturing and turnaround refracture technology were analyzed, wells selective and layers selective principles and optimization designing of operation parameters of turnaround fracture technology were formed,which produced significant effects in lower permeability oil fields.This paper also proposed the methods of estimating fracture length and the seepage area of the turnaround refracture and achieved good results through the on-site applications for the low permeability oil fields in northern Shaanxi,which greatly increased the production.It may provide guidance for the transformation of the old wells in similar reservoirs.