This study explores a safe and effective new approach to improve language function in children with Global Developmental Delay (GDD). Conducted at Xiangxi Autonomous Prefecture People's Hospital, the study will recruit approximately 50 children aged 2 to 5 years. Participants will be randomly assigned to one of two groups: one receiving personalized language training combined with non-invasive, painless repetitive Transcranial Magnetic Stimulation (rTMS) to activate language regions of the brain, and a control group receiving personalized training for comparative analysis. The study spans one month, including a two-week intervention period followed by a two-week follow-up to evaluate the efficacy and sustainability of the combined therapy. This study has been rigorously reviewed and approved by the hospital's Ethics Committee.

Inclusion criteria

1. Children aged 2-5 years old, regardless of gender.
2. Meet the diagnostic definition of GDD in China's Diagnostic Guidelines for Global Developmental Delay (2024), confirmed by Gesell Developmental Schedules (GDS). Language domain Developmental Quotient (DQ) ≤ 75. A DQ ≤ 75 is found in at least one of the four developmental domains: gross motor, fine motor, adaptive behavior, and personal-social conduct. Mild-moderate GDD is selected for the study.
3. The presence of significant language developmental delay, the language ability is significantly lower than children of the same age and the same intellectual level, confirmed by the standardized scale of Sign-Significate Relations (S-S) assessment.
4. The child is able to cooperate with the completion of rTMS treatment and language assessment and has no serious behavioral problems.
5. Written informed consent obtained from the child's legal guardian. Exclusion Criteria

1. History of epilepsy or convulsive seizures. 2. Having metal implants in the skull (e.g. aneurysm clips, metal stents, etc.) and electronic devices such as pacemakers and cochlear implants in the body.

3. Other serious neurological conditions that may affect language function (e.g., cerebral palsy, progressive neurological disorders, etc.).

4. Have a diagnosis of ASD. 5. Have a severe hearing or visual impairment. 6. Participation in other clinical trials that may affect speech function. 7. Skin lesions or infection at the scalp treatment site. 8. The fontanelle has not yet closed. 9. Previous rTMS treatment in the last 3 months. 10. Developmental quotient < 40 in any developmental domains; other circumstances that prevented cooperation with the study.

The language therapists providing individualized training and the outcome assessors conducting language evaluations will all be blinded to group allocation. Outcome assessors will have no involvement in the randomization or intervention processes.