Sagittal sequences of the spine have been shown to correlate with knee osteoarthritis (KOA), but coronal sequences and KOA have never been studied before. The study required patients to use a standard standing posture and aimed to explore the relationship between coronal position of lumbar spine and WOMAC score in KOA. This is a cross-sectional observational study. Data on a total of 268 patients with KOA were collected. Patients were photographed in a standard standing position and lumbar-sacrum offset distance (L-SOD) and lumbar-knee offset distance (ΔL-KOD) were calculated. Patients were then divided into different groups according to different critical values and differences were compared. In the L-SOD of L1-3, WOMAC function (P = 0.021, P = 0.032, P = 0.001) and total score (P = 0.039, P = 0.034, P < 0.001) were different. In the L-SOD of L3-4, WOMAC pain score were different (P = 0.001, P = 0.032). At a cutoff of 13mm, ΔL-KOD of L1-2 showed significant differences in pain part (P = 0.025, P = 0.039) and total score (P = 0.036, P = 0.050). There were significant differences in pain (P = 0.023, P = 0.027, P = 0.022), function (P = 0.048, P = 0.038, P = 0.047), and total score (P = 0.030, P = 0.027, P = 0.029) of L3-5. In the 18-mm cutoff group, only L1 and L2have differences in the pain part (P = 0.050, P = 0.038). Coronal balance of the lumbar spine is associated with knee pain and function. The pelvis plays an important role in maintaining the coronal balance. Both the lumbar spine and the knee joint should be considered when developing the surgical strategy.