Background Port-wine stain (PWS) is a congenital vascular malformation, frequently appearing at the face and neck. Hemoporfin photodynamic therapy (HMME-PDT) is a new technology for treating PWS. Pain is one of the major and intractable side-effects in this treatment. Compound lidocaine cream is widely utilized for local anaesthesia for good curative effect. Objectives To investigate the degree of pain in the patients treated by HMME-PDT and evaluate the analgesia effects of compound lidocaine cream. Methods Patients were divided into two groups randomly. For treatment group, the compound lidocaine cream with the dose of 2g/cm2 was occluded for 2 hours before treatment, and placebo for control group. We used ChangHai rating scale to record pain scores every minute during the treatment. Results 78 patients were included and divided into test group and control group. Pain occured at the beginning of treatment and increased in the first 16 minutes by time, then stabilized. There was a significant difference between the two groups about the association of pain and treatment time (P＜<0.05), but no significant difference of pain scores at each minute(P <0.05). Different factors such as location, size and types of lesion were compared and showed no significant difference of pain scores. Conclusions From this trial, we found that the pain during treatment started at the beginning and got worse in the first 16 minutes by time, then stabilized. Accordingly, compound lidocaine cream could not release the pain during treatment.