Bond dissociation energies of a series of substituted silanes were studied with the density functional theory methods. The performances of six different density functional methods including B3LYP, B3P86, BH&HLYP, B1LYP, PBE1KCIS, and TPSSLYP1W were examined for the prediction of Si–H bond dissociation energies. The results showed that B3P86 was the most accurate theoretical procedure among these six DFT methods. Using the B3P86 method, we then carried out a systematic study about the substituent effects on Si–H bond dissociation energies, with a focus to identify the possible approaches to weaken the Si–H bond strength. On the basis of the knowledge learned from the systematic study on model systems, we proposed some new silicon-based radical reducing reagents which may be used to replace toxic tin hydride reagents.