Abstract: In order to obtain the tensile strength of cemented tailings backfill scientifically, a direct tensile test suitable for cemented tailings backfill is proposed in this paper, and the corresponding test apparatus is developed, including a loading frame and a five-part split mold.The test is carried out to measure the tensile strength of backfill with different cement-sand ratio, slurry solid content and curing ages.Based on the test data, the relationship between tensile strength of cemented tailings backfill and the three factors is analyzed by single-factor analysis.The sensitivity of tensile strength to these three factors is also studied.The relationship between the tensile strength of cemented tailings backfill and cement-sand ratio, slurry solid content and curing ages can be expressed as linear function, exponential function and logarithmic function respectively.The sensitivity of tensile strength of cemented tailings backfill to the change in cement-sand ratio is highest, but it is the lowest to curing ages.The test method and study results in this paper can provide a reference for the formation of a standardized test method for determining tensile strength of cemented tailings backfill.