Through casing logging refers to the research on reservoir identification, reservoir physical property evaluation and water-flooded zone evaluation on the basis of the casing well survey in the exploration well or development well after casing cementing. In the early stage, casing-through logging is mainly used in reservoir dynamic monitoring, remaining oil distribution monitoring, well area water flooding effect, water-flooded zone analysis and other aspects in the development logging. Because of its convenient and practical characteristics, it is widely used in oilfield production. In recent years, due to the increasing number of highly deviated wells, horizontal wells, high temperature and high pressure and other high-risk complex structure exploration wells, in order to reduce the probability of logging operations and shorten the logging period, casing-through logging can be used to replace the original open hole logging.It is worth noting that for cased hole logging, due to the isolation of casing and the influence of borehole and formation, the detection range is smaller than that of open hole logging, and the evaluation results of oil and gas reservoirs are in doubt.Through the analysis of the logging principles of casing through resistivity , neutron and density , the influencing factors of casing through logging response are clarified and the corresponding correction processing is carried out. On this basis, the comprehensive interpretation of the reservoir is carried out, which effectively solves the difficulty of casing through logging evaluation technology.