Objective To introduce the surgical technique and preliminary clinical results of percutaneous cannulated screws in the treatment of Day typeⅡcrescent fracture dislocation of pelvis under navigation. Methods From January 2015 to December 2018, 23 patients with Day typeⅡcrescent fracture dislocation of pelvis were treated with the above surgical methods. Mimics 17.0 software was used to plan screws fixation before operation. Orthopedic 3D navigation was used during the operation. After the tracker was installed, the registration of navigation was completed centering on the sacroiliac joint on the affected side to obtain the relative position of the crescent fracture line passing through the sacroiliac joint. Under navigation, sacroiliac screws were used to fix the sacroiliac joint in front of the crescent fracture, and then LC-Ⅱ screws were placed under the navigation "teardrop" position. Then use the CLIC point as the needle entry point to drill in the second screw parallel or (in the shape of "eight") to the LC-Ⅱ screw. Results Twenty-three patients successfully completed the operation without complications such as neurovascular injury. The time of LC-II screw placement was 1.8～3.0 min with an average of (2.32?0.34)min. The screw positions were assessed by Gras classification, with a safe screws placement rate of 95.6%（22/23. According to the Matta imaging criteria, the excellent and good rate was 91.3%（21/23）. The Majeed functional score at 6 months after operation was significantly improved compared with that before operation (P<0. 01). One sacroiliac screw loosened, and one posterior iliac screw penetrated the medial cortex of the bone. Conclusion The percutaneous cannulated screws in the treatment of Day typeⅡcrescent fracture dislocation of pelvis under navigation has the advantages of low radiation exposure, high accuracy of screw placement, satisfactory anatomical reduction, good functional recovery.