Objective To analyze the diagnosis value of dual-slice CT and plain X-ray in lumbar disc herniation. Methods 40 lumbar disc herniation patients treated in our hospital were investigated. Dual-slice CT and plain X-ray were performed.Imaging features were analyzed. According to surgical and pathological results, diagnosis accordance rate of single examination and combined examination was compared. Results Based on surgical and pathological results, diagnosis accordance rate of lumbar disc herniation positions based on combined examination (100%) was significantly higher than that of plain X-ray (47.5%) and dual-slice CT (90%)(P＜0.05); diagnosis accordance rate of disease classifications based on dual-slice was 95%; there was no significant difference with surgical and pathological results (P＞0.05). X-ray results indicated the abnormal lumbar vertebral space width and length,physiological curve of lumbar vertebra in arciform and warped state. CT results indicated slipped disc in vertebral edge, low density than that of intervertebral disc, proliferated facet joint, irregular nodes, lateral recess stenosis, large masses, soft tissue density image, dural sac, and deformed, displaced or even disappeared nerve root. Conclusion Both of X-ray and CT have its advantages for diagnosis of lumbar disc herniation; however, single examination is prone to have the misdiagnosis and missed diagnosis events. Therefore, combined examination can increase the diagnosis accordance rate and provide reliable imaging basis on clinical treatment.