The temperature effect of the strong coupling bound polaron in a parabolic quantum well is studied theoretically, and the expressions of the polaron ground state energy and the ground state binding energy are derived by using the linear combination operator and the unitary transformation methods. The ground state energy and ground state binding energy of polaron are functions of the vibration frequency, electron phonon coupling strength, Coulomb bound potential strength, well width and well depth, respectively. At finite temperature, the electron phonon system will no longer be complete in the ground state. The lattice vibration not only excites the real phonon, but also excites the electron. The properties of polaron are mainly determined by the statistical average of various states of electron phonon system. The expression of the average phonon number of polaron is also obtained through theoretical calculation. Combined with quantum statistics, the functional relationship between the ground state energy and ground state binding energy of polaron and temperature is obtained. By numerical calculation, the polaron ground state energy and ground state binding energy are increasing functions of temperature. When thetemperature is set to a fixed value, as the electron-phonon coupling strength, Coulomb bound potential strength and well width increase, the ground state energy of the polaron decreases and the ground state binding energy increases. With the increase of the well depth, the ground state energy of the polaron increases, and the ground state binding energy decreases.