To explore the effects of tissue expansion on the anastomoses and the survival of the axial pattern flap with a crossing area supply so as to improve the survival of crossing area axial pattern flap and to provide a new idea for the development of original crossing area axial flap. Methods The experiment included two parts. Experiment A was divided into expansion group and control group. Square flaps were randomly designed on own control bilaterally in each animal with a boundary of midl ine. Experiment B was divided into expansion group and delay group. The flaps were also randomly designed on own control bilaterally. Angiographic analysis and gross survival observation were carried on. Results ExperimentA: Angiography showed that there were abundant anastomoses with big cal iber between deep il iac circumflex artery and superior epigastric artery in expansion group and there were only 3-4 anastomoses in control group. Experiment B: Angiography showed that there were abundant anastomoses with big cal iber in expansion group and there were two arterial systems with relatively less anastomoses and smaller cal iber in delay group. The survival rates in expansion group was significantly higher than that in the control group (90.16% ± 3.61% vs 72.67% ± 5.35%) in experiment A, and in experiment B the survival rate was 92.08% ± 3.30% in the expansion group and 80.79% ± 4.52% in the delay group, showing significant difference (P lt; 0.01). Conclusion Expansi on prefabrication can and improve the survival of the crossing area supply axial pattern flap. The mechanism is the bridging effect.