This study aimed to investigate the treatment efficacy of free bone retention plus iliac bone grafting under phase I Vacuum Sealing Drainage (VAS) lavage for treatment of open bone defects. Thirty-six bone fractures were classified according to the Gustilo classification between January 2008 and April 2016. This study included 16 type I cases, 12 type II cases, and 8 type IIIA cases. Length of the longitudinal section of the damaged free crushed bone was 0.5 to 7.1 cm. There were 7 cases with sections ≤ l cm, 12 with sections 2 to 3 cm, 11 with sections 3 to 5 cm, and 6 with sections>5 cm. The rinse protocol comprised 3000 ml/d of saline for 3 days for Gustilo type I fractures, 6000 ml/day of saline for 5 days for Gustilo type II fractures, and 9000 ml/d of saline for 7 days for Gustilo type IIIA fractures. Fifty ml of Anerdian (type III, diluted 10 fold) was added by VSD treatment (closed negative-pressure lavage). Callus formation was seen within 3.5 months after surgery, with osseous union at an average of 6.5 months. The wound healed well in 35 cases. In l case, the patient developed superficial cellulitis near the screw path, which resolved after removing the external fixation device. There was no internal fixation loosening, breakage, or exposure. Non-union and osteomyelitis were not seen. This method could be effective to prevent infection, osteomyelitis, delayed union, and non-union.