Abstract: A method is presented for calculating the wellbore temperature field during the fracture treatment of horizontal well is presented in this paper.The calculation of temperature field in horizontal well can be divided into three parts:1.straight section;2.kick-off section;3,horizontal section.The computation for the straight section has been discussed by other researchers.This discussion focuses mainly on the kick-off section and horizontal section.This method,slices finitely the wellbore of the kick-off section,and changes the boundary conditions of the horizontal section,and then the heat conduction equations are established for every unit.By solving these equations,we will get the wellbore temperature in any time and any position.A field example is provided in this paper.