To observe the efficacy and safety of finasteride combined with botulinum toxin type A injection in the treatment of androgenetic alopecia (AGA). Methods A total of 47 male patients with AGA admitted to Sir Run Run Shaw Hospital, Zhejiang University School of Medicine from June 2021 to August 2022 were randomly divided into control group (n =23) and observation group (n =24). The control group was treated with type A botulinum toxin injection, while the observation group was treated with finasteride combined with type A botulinum toxin injection. The hair density, proportion of terminal hair/lanugo hair, quality of life and adverse reactions were compared between the two groups. Results The scores of hair density in the observation group were higher than those in the control group after 3 and 6 months of treatment (P <0.05). There was no significant difference in the ratio of terminal hair/lanugo hair between the two groups at 3 and 6 months of treatment (P >0.05). The scores of scalp greasy degree, pruritus, scales and alopecia in the observation group were higher than those in the control group (P <0.05). There were no obvious, serious side effects and adverse reactions in the two groups. Conclusion The clinical effect of finasteride combined with type A botulinum toxin injection in the treatment of AGA is good, which can improve the hair density of patients and their quality of life, and the application safety is high.