This standard specifies a method for the determination of nickel content in titanium-nickel shape memory alloys, which is applicable to titanium-nickel alloys with a nickel content range of 50.00% to 60.00%. The test method includes dissolving the sample with mixed acid, complexing titanium and Miscellaneous elements with citric acid, and separating nickel by dimethylglyoxime settling under the condition of pH value of 9 to 10. After settling, the nickel is dissolved with muriatic acid and complexed with EDTA at pH 6. Xylenol orange is used as an indicator, and back titration is carried out by standard titration solution of zinc chloride. This method can effectively separate and measure the nickel content and ensure the accuracy of the analysis results.