Objective: To observe the clinical efficacy and safety of different concentrations of aminolevulinic acid photodynamic therapy (ALA-PDT) in the treatment of solar keratosis (AK). Method: 48 AK patients admitted to the dermatology outpatient department of Baoshan People"s Hospital from April 2021 to April 2024 were selected as the research subjects. According to the 1:1 random coin toss principle, they were divided into a control group and an observation group, with 24 cases in each group. Both groups were treated with ALA-PDT, with the control group receiving a 10% concentration of medication and the observation group receiving a 20% concentration of medication. Compare the clinical efficacy, incidence of adverse reactions, and pain severity scores between two groups. Result: The effective rate of treatment in the observation group was higher than that in the control group, and the incidence of adverse reactions and pain scores were lower than those in the control group (P<0.05). Conclusion: Compared with 10% concentration solution, ALA-PDT with 20% concentration solution has higher therapeutic effect, higher safety, and can reduce the degree of body pain in the treatment of AK.