Objective To compare the clinical efficacy of phencyclidine ammonium bromide nasal spray and mometasone furoate nasal spray in patients with moderate-to-severe allergic rhinitis (AR). Methods 200 patients with moderate-severe AR admitted from May 2020 to May 2023 were selected and grouped by randomized numerical table method, 100 cases in the control group were treated with mometasone furoate nasal spray, and 100 cases in the study group were treated with phencyclidine quinclorac bromide nasal spray, and the two groups were compared in terms of clinical efficacy, nasal symptom scores and quality of life. Results The total effective rate of the study group was higher than that of the control group (93.00% vs. 82.00%) (χ2=5.531, P=0.018); the scores of nasal congestion, sneezing, itchy nose ,and shed tears of the two groups were lower than those of the same group before the treatment after 2 weeks of the treatment, and the lowering of the study group was more obvious than that of the same group before the treatment after 4 weeks of the treatment, and the lowering of the study group was more obvious than that of the same group before the treatment. After 4 weeks of treatment, all RQLQ scores of both groups were reduced compared with those of the same group before treatment, and the reduction was more obvious in the study group (P < 0.05). Conclusion The treatment of moderate-severe AR patients with phencyclidine ammonium bromide nasal spray and mometasone furoate nasal spray can achieve good efficacy, and the former has better efficacy in comparison, which can rapidly improve the patient's symptoms and is conducive to improving the quality of life.