Objective In order to find out the failure cause of oil well tubing and sucker rod. Methods The macroscopic morphology of failure sample of tubing and sucker rod was observed. Chemical composition, microstructure and microcosmic fracture surface were analyzed. Tensile strength, lower yield strength, elongation and reduction of area of sucker rod were tested. Meanwhile, tensile strength, yield strength, elongation and impact energy were tested. The failure reasons were analyzed according to the results of laboratory tests combined with working condition, properties of the output liquid, corrosion coupon testing data and tubing thread connection structure. Results The tensile strength of sucker rod was 910 MPa, lower yield strength 845 MPa, elongation 17%, and reduction of area 67.5%. All the test results were in line with SY/T 5029—2013 Sucker Rods. The microstructure pearlite+ferrite was normal. The phosphorus and sulfur contents were 0.015% and 0.011% respectively, tensile strength 725 MPa, yield strength 445 MPa, elongation 26.0% and impact energy 27 J. All the test results were in line with API Spec 5CT Specification for Casing and Tubing. The microstructure pearlite+ferrite was normal. Conclusion The tubing and sucker rod failure are caused by eccentric wear and corrosion. J value groove is an important reason of the tubing and sucker rod failure. We can slow down eccentric wear by controlling the J value at 0 and changing from impact wear to sliding wear.