(1) Background: Primary intraspinal tumors account for 2-15% of all central nervous system (CNS) tumors. Most intraspinal tumors are benign, and about 40% of them occur intradurally, for which early surgery is the preferred treatment. Laminectomy with pedicle screw fixation is the conventional surgical treatment. However, laminectomy with pedicle screw fixation is likely to reduce the spinal range of motion (ROM), with many other complications, although it can maintain the stability of the spine. The aim of this study is to determine whether laminoplasty as a new surgical approach for thoracic and lumbar intradural tumors is superior to laminectomy in preserving spinal ROM, maintaining spinal stability and reducing postoperative complications. (2) Methods: We retrospectively analyzed 50 patients who received intradural tumor resection, including 23 who received traditional laminectomy with pedicle screw fixation and 27 who received new laminoplasty. Spinal ROM was evaluated by lumbar flexion/extension radiograph and biomechanical evaluation. Spinal stability was evaluated by imaging observations of the spinal Cobb angle and laminar bone fusion. Postoperative complications were evaluated according to cerebrospinal fluid (CSF) leakage and the length of hospital stay. (3) Results: Compared with the laminectomy group, patients in the laminoplasty group exhibited a better spinal ROM (31.6 ± 12.0° vs. 21.7 ± 11.8°, p = 0.013), a smaller Cobb angle (9.6 ± 4.3 vs. 12.5 ± 5.3, p = 0.034), a lower incidence of CSF leakage (4/14.8% vs. 11/47.8%, p = 0.015), and a shorter length of hospital stay (13.1 ± 1.8 vs. 15.1 ± 2.3 days, p = 0.001). Most patients in the laminoplasty group had satisfactory bone fusion. The biomechanical experiment also demonstrated that spinal ROM in laminoplasty was larger than that in the laminectomy group. (4) Conclusions: Compared with the traditional surgery, the new laminoplasty surgery can better maintain the stability of the spine, preserve spinal ROM, and reduce postoperative complications. It is a surgical method that can be clinically popularized.