Objective: To comparatively study the clinical application value of magnetic resonance sT2W-3D-FFE water imaging technology in the imaging of lumbosacral plexus nerve compression injury diseases. Methods: Thirty-five patients with positive clinical symptoms such as lower extremity pain and numbness and suspected lumbosacral plexus nerve symptoms admitted to our hospital from January 2023 to October 2024 were selected as the research subjects. All patients underwent routine MRI examinations of the lumbosacral vertebrae [T1WI/sag, T2WI-mDixon/sag, T2W/tra], MRN of the lumbosacral plexus nerve, and magnetic resonance examinations using the sT2W-3D-FFE water imaging technique. The clinical surgical results combined with the patient"s chief complaint, electromyography, and comprehensive examination results of nerve conduction velocity were taken as the gold standard for diagnosing lumbosacral plexus nerve compression injury. To analyze and compare the diagnostic results and efficacy of magnetic resonance images of different sequences in the diagnosis and treatment of lumbosacral plexus neurological symptom diseases. Results: Among the 35 patients with suspected lumbosacral plexus nerve symptoms, 31 patients were finally diagnosed with lumbosacral plexus nerve compression injury. There were no significant differences in the sensitivity and specificity of the three examination methods for the diagnosis of lumbosacral plexus nerve entrapation injury (P>0.05). However, there were significant differences in the diagnostic accuracy among the three groups (P<0.05). The AUCs of conventional MRI, MRN and water imaging for diagnosing lumbosacral plexus nerve entrapation injury were 0.793, 0.815 and 0.901, respectively. The results of comprehensive image analysis showed that the magnetic resonance sT2W-3D-FFE water imaging technique was superior to the routine magnetic resonance examination of lumbosacral vertebrae and lumbosacral plexus nerve MRN alone in terms of the location of the lesion tissue. Conclusion: Magnetic resonance sT2W-3D-FFE water imaging technology has higher imaging diagnostic value and clinical application value in the diagnosis and treatment of lumbosacral plexus nerve entralment diseases.