The influences of temperature and polaron effect on the ground state of the system，for which the exciton is strongly coupled with interface-optical (IO) phonons but weakly coupled with bulk-longitudinal-optical (LO) phonons in a quantum well, are studied by using the Huybrechts' linear-combination operator and Lee-Low-Pines (LLP) transformation method. The expressions for the induced potential and energy shift of the ground state of the exciton were derived. Numerical calculations for AgCl/AgBr QW, as an example, are performed. The result indicates that the induced potential and the energy shift increases for strong exciton-IO-phonon coupling but decreases for weak exciton-LO-phonon coupling with temperature.