In order to avoid failure of the half grout sleeve splice of rebars in prefabricated concrete structures after fire and serious consequences，27 14 mm-half grout sleeve splicing specimens of rebars were manufactured to study their mechanical properties by unidirectional static tensile test after high temperature. The test results showed two failure modes of the specimens after high temperatures including fracture and pull-out of rebars, in which the latter one was more likely to occur when the specimens were cooled by water. During the tensile process, the relative slip can occur between the sleeve and the rebar connected at the grouting side, and the slip increased nonlinearly with the increase of the temperature. Based on the test results after 600 ℃ high temperature and the existing bond strength formulas，suggestions were given to avoid the pull-out failure of rebars after high temperature. According to approximate analysis of steel slip in elastic stage，the quadratic function curve between the slip and temperature under natural cooling after high temperature was obtained.