Objective To investigate the value of 18 fluorodeoxyglucose (18F-FDG) PETCT combined with serum squamous cell carcinoma antigen (SCC-Ag) in diagnosing pelvic lymph node metastasis of cervical cancer. Methods A total of 56 patients with cervical cancer who were treated in the hospital from January to September 2017 were selected as the subjects. All patients underwent 18F-FDG PET-CT, serum SCC-Ag examination and 18F-FDG PET-CT combined with serum SCC-Ag detection. With postoperative pathological results or follow-up (follow-up time was 6 months) results as the golden standard, the value of the three in the diagnosis of pelvic lymph node metastasis of cervical cancer was evaluated. Results The sensitivity, specificity and accuracy of 18FFDG PET-CT combined with serum SCC-Ag in the diagnosis of pelvic lymph node metastasis of cervical cancer (91.67%, 85%, 89.29%) were higher than those of 18FFDG PET-CT or serum SCC-Ag (69.44%/75.00%, 80.00%/65.00%, 73.21%/71.43%). Conclusion The sensitivity, specificity and accuracy of 18F-FDG PET-CT combined with serum SCC-Ag detection are high in the diagnosis of pelvic lymph node metastasis of cervical cancer.