Although the identification of pipelines′ inner boundary based on heat conduction has been matured, the quantitative identification of inner boundary of turbulent pipe, which is more practical, has scarcely been reported yet. The steady-state identification of the inner boundary shape of a turbulent pipe with fully developed two-dimensional axial symmetry was studied through the connection of COMSOL and MATLAB, as well as the use of finite element method and Levenberg-Marquardt method. The validity of this method was proved by numerical experiments. The results show that, in a turbulent pipeline with a defective inner boundary, the maximum temperature difference of outer wall and the absolute temperature difference caused by defect do not increase synchronously. During the identification of inverse inner boundary problem, due to the negative growth in the absolute temperature difference, the identification results do not necessarily improve with the increase of absolute temperature difference. The identification accuracy slightly deteriorates at the end of the irregular inner boundary.