In order to explore the expression of bHLH transcription factor in the process of iron deficiency retrieved green of pear leaves, we screened the key bHLH genes in response to the process to provide a theoretical basis for improving the iron deficiency resistance of pear varieties. Normal and chlorotic plants of ‘Dangshansuli’ (Pyrus bretschneideri Rehd.) were taken as test material. We sprayed 0.2% FeSO₄(2 g·L^-1 FeSO₄) solution on the chlorotic leaves and distilled water were used for both normal (N) and chlorotic (C) leaves as control during the growing season. The leaves and tender root hair of normal, chlorotic plants and retrieved green leaves on 3rd, 6th, 9th, 12th day after FeSO₄ application were taken as samples for transcriptome data analysis, and the differentially expressed bHLH genes were screened, supplemented by fluorescence quantitative PCR. The expression and biological characteristics of the genes in leaves and roots were analyzed, and the correlation with Fe²⁺ content in leaves were analyzed. The results indicated that: (1) transcriptome data showed that there are 21 bHLH genes were significantly differentially expressed in chlorotic leaves at N, C and different stages after treatment with FeSO₄, involving 11 subclasses, and their motifs number ranged from 1 to 10. (2) qRTPCR showed that the expression of PbrbHLH7/29/41/104/119/122/128/155/183/191 in C leaves was significantly higher than that in N leaves. After FeSO₄ treatment, the expression of them were significantly lower than that in C leaves in different stages; In contrast, the expression of PbrbHLH15/46/53/69/78/89/115/137/144 in C leaves were significantly lower than that in N leaves. After FeSO₄ treatment, the expression of them were significantly higher than that in C leaves in different stages. (3) Consistent with the difference in the expression level in aboveground leaves, the expression of PbrbHLH29/41/119/128/155/183/191 in C roots were also significantly higher than that in N roots, while the expression of PbrbHLH53/89 in C roots was also significantly lower than that in N roots. (4) The correlation analysis showed that the content of Fe²⁺ in leaves was significantly negatively correlated with the expression of PbrbHLH41 and positively correlated with PbrbHLH78 in different stages after FeSO₄ solution treatment. In conclusion, the iron deficiency retrieved green of pear leaves regulated by exogenous FeSO₄ treatment may be closely related to the synergistic changes of bHLHs expression in leaves and roots of pear. PbrbHLH41/78 may play an important and antagonistic regulatory role in this process, which can be considered as candidate genes to study the mechanism of iron deficiency retrieved green of pear leaves.