Gibberellic acids (GAs) play a crucial role in regulating fruit size, although the underlying mechanisms remain elusive. This study aimed to delineate the regulatory mechanisms of exogenous GAs in pear fruit development by examining the physiological indicators in fruit pulp samples. RNA-Seq analysis unveiled 2,140 differentially expressed genes following exogenous GA treatment. By analyzing the response of different genes to exogenous GAs, we speculated that PyTRM may be a key player in GA-mediated fruit development. We identified 50 TRM genes from the pear genome and classified them into three subfamilies using phylogenetic analysis. Nine of these genes exhibited a significant response to the exogenous application of GAs, with PyTRM112 identified as a promising candidate for GA-mediated fruit development. Overexpression of PyTRM112 in Arabidopsis revealed its positive regulatory role in growth and development. Gene interaction networks indicated the potential involvement of these nine genes in the catalytic activity of tRNA methyltransferases. This study establishes a solid foundation for understanding the mechanism of GA-mediated fruit development by shedding light on the significant role of TRM family genes in regulating fruit shape and size after GA application.