This study aims to develop and evaluate a novel therapeutic strategy for Alzheimer's disease (AD) by overcoming the blood-brain barrier (BBB) limitations of Neurotrophin-3 (NT-3). NT-3, a critical neurotrophic factor, plays essential roles in hippocampal neuron growth, survival, and synaptic plasticity, making it a promising candidate for AD treatment. However, its clinical application is hindered by its inability to cross the BBB. To address this, we utilized genetic engineering techniques to fuse the TAT transmembrane peptide with NT-3, producing a recombinant NT-3 (T-NT-3) with enhanced membrane-penetrating capability. Protein characterization confirmed that T-NT-3 possesses good stability and the ability to cross the BBB. In vitro experiments demonstrated that T-NT-3 inhibits oxidative stress, apoptosis, and inflammatory responses in neural cells by activating TrkC receptors and suppressing M1 microglial activation. In vivo, T-NT-3 improved cognitive and memory impairments in APP/PS1 mice and reduced AD-associated pathological changes. These findings highlight the mechanisms by which T-NT-3 alleviates hippocampal neurotoxicity, providing a foundation for its future application as a recombinant protein therapy for AD.