To analyze the clinical effect of secukinumab in the treatment of moderate to severe plaque psoriasis. Methods A total of 60 patients with moderate to severe plaque psoriasis admitted to our hospital from January 2022 to January 2023 were selected as the research objects. They were divided into control group and study group by random number table method, with 30 patients in each group. The control group was treated with acitretin capsules, and the study group was treated with secukinumab. The psoriasis area and severity index (PASI) and dermatological quality of life index (DLQI) were compared between the two groups at 4, 8, 12 and 16 weeks after treatment. The response rates of PASI 75 and PASI 90 were calculated, and the occurrence of adverse drug reactions was monitored throughout the treatment. Results The PASI score and DLQI score of the study group were lower than those of the control group at 4, 8, 12 and 16 weeks after treatment (P <0.05). The response rates of PASI 75 and PASI 90 in the study group were higher than those in the control group at 4, 8, 12 and 16 weeks after treatment (P <0.05). The incidence of adverse reactions in the study group was 6.67%, which was lower than 16.67% in the control group, and the difference was statistically significant (P <0.05). Conclusion Compared with acitretin capsules, the application of secukinumab in the treatment of moderate to severe plaque psoriasis can accelerate the clearance of skin lesions, effectively relieve clinical symptoms, improve the quality of life, and the incidence of adverse reactions is low.