The iridium hydride complexes have been extensively used in organic reactions, such as oxidation and hydrogenation reactions. In many of these reactions, the dissociation or formation of Ir-H bond plays an important role in determining the overall reaction rates and yields. In the present study, the accuracy of different theoretical methods for prediction of Ir-H bond strengths has been examined on the basis of the previously reported Ir-H BDEs of 17 different complexes. Comparing the performance of different DFT functionals (e.g. B3LYP, TPSS, M06), different basis sets (including the different effective core potentials (ECP) on Ir and I atoms, and the total electron basis sets on the other atoms), and different solvation models (SMD, CPCM, and IEFPCM) in solution phase single point calculations, we found that the gas-phase calculation with TPSS/(LanL2DZ: 6-31G(d)) method is relatively more accurate than the other gas-phase calculation methods, and can well simulate the Ir-H BDEs in low-polarity solvents (such as chlorobenzene and dichloroethane). Finally, efforts were put in analyzing the structure-activity relationships between the ligand structure (around Ir center) and the Ir-H BDEs. We wish the present study could benefit future studies on the Ir-H complexes involved organic reactions.