The invention relates to a sample for high-temperature testing tensile strength of a conductive composite material and a method thereof, which belong to the field of high temperature mechanical properties testing of the composite material. According to the invention, an upper V-shaped groove and a lower V-shaped groove are respectively arranged on an upper surface and a lower surface of a sample along a direction of a pavement layer, U-shaped gaps are respectively arranged at the bottom of the upper V-shaped groove and the top of the lower V-shaped groove, and a V-shaped angle of the upper V-shaped groove and the V-shaped angle of the lower V-shaped groove are 120 DEG. The method is characterized in that before testing, a caliper is used for measuring a thickness b and a width w of any three places of a gauge length zone of a sample, and data is recorded; the sample is positioned between two graphite pressure heads in a stable mode, central axis of the sample, central axis of two graphite pressure heads and axis of a pressure bar of a testing machine are superposed; the test piece is applied with 5% of preliminary load which is not greater than a intensity desired value; a heatingrate is set for uniformly heating the test piece; loading is carried out according to constant displacement until a sample is fractured, displacement and load data in the tests are recorded; and the test stops; and the high-temperature tensile strength sigma ILT of the composite material is calculated. The sample is used for testing the high-temperature tensile strength of the conductive compositematerial.