Objective To explore the diagnostic effect of procalcitonin on sepsis in burn patients. Methods A total of 86 burn patients admitted to the 80th Group Military Hospital of the Chinese People's Liberation Army from January 2022 to June 2023 were selected as the research objects. According to whether sepsis occurred, they were divided into two groups: sepsis group (n=43) and control group (n=43). According to the degree of infection, they were divided into mild infection group (n=11), moderate infection group (n=18) and severe infection group (n=14). The levels of serum procalcitonin (PCT), C-reactive protein (CRP) and white blood cell (WBC) in different groups were compared. Results The levels of PCT, CRP and WBC in the sepsis group were higher than those in the control group, and the difference was statistically significant (P<0.05). There was no significant difference in CRP and WBC levels among the three groups (P>0.05). the level of PCT in the moderate and severe infection groups were higher than those in the mild infection group and the difference was statistically significant (P<0.05). Conclusion Procalcitonin is effective in the diagnosis of sepsis in burn patients, which can identify different degrees of infection and early diagnosis of sepsis, and has high clinical value.