The effect of antisense epidermal growth factor receptor (EGFR) nanoparticles on the radiosensitivity of squamous cell carcinoma in mice was studied. Antisense EGFR oligonucleotide nanoparticles were introduced into the SCCVII cell line, and the expression of the antisense EGFR in the SCCVII cell line was detected using western blot analysis. After radiotherapy intervention, a cell cloning test and MTT test were used to detect the radiosensitivity of the cells, and flow cytometry was used to detect the cell cycle distribution and apoptosis to establish a model of head and neck cancer in mice. Antisense EGFR nanoparticles were injected into the tumors and treated with 4 Gy radiation therapy to observe their inhibition on the growth of tumors. SCCVII cell line nanoparticles could significantly inhibit the expression of antisense EGFR proteins. The combination of antisense EGFR nanoparticles and radiotherapy could reduce the differentiation and division ability of cancer cells (P < 0.05). It could arrest cancer cells in the G1 phase and significantly increase the apoptotic rate (P <0.05). The growth of tumors in the antisense EGFR nanoparticles group was significantly delayed. Antisense EGFR nanoparticles could induce G1 phase arrest by down-regulating the expression of EGFRs, which had a radiosensitization effect.