Objective　To investigate the anatomical characteristics about modified minimally invasive surgery TILF by muscle space approach and bilateral fixation and unilateral decompression, and to analyze the clinical efficacy comparison of traditional surgical treatment of lumbar degenerative disease.　Methods　From December 2014 to December 2016，60 patients of lumbar degenerative disease, underwent one-level instrumented TLIF procedure using 2 different approaches(modified minimally invasive surgery by muscle space approach and bilateral fixation and unilateral decompression in 30 patients and traditional approach in 30 patients) by one group of surgeons．The anatomical characteristics about modified minimally invasive surgery TILF was then studied. The following data were compared between the 2 groups：surgical time，blood loss, postoperative drainage volume. The patients were followed up with VAS and Oswestry scores in Preoperative and 2 weeks after operation.　Results　The modified group was treated with bilateral minimally incision, one side was purely fixed by Wiltse gap approach, and the other side was decompressed，fused in the vertebral body and fixed by the modified intermuscular gap approach (the near center gap of multifidi). There was no obvious difference in VAS and Oswestry scores in preoperative or Oswestry scores in 2 weeks after operation (P>0.05)，but less surgical time，blood loss，postoperative drainage volume and lower VAS scores in Oswestry scores in 2 weeks after operation were notified in modified group（P<0.05）. Conclusions　Compared with the conventional approach，the modified minimally invasive surgery TILF being more adaptable to human anatomical characteristics can result in easier operation, and better surgical vision. Meanwhile, the modified group can get less surgical time，blood loss，Postoperative drainage volume and low postoperative pain．It is worthy of clinical promotion.