Abstract: In order to establish repeated blood collection and long-term infusion venous access, and to improve the efficiency of continuous dynamic blood collection and intravenous administration, the experiment took 3 ewes as experimental animals, conducted the research on the use of modified Seldinger technique to insert central venous catheter in the middle of the neck, and then performed blood collection and intravenous infusion effect evaluation. The blood routine indexes were tested before and after the catheter was installed, the influence of central venous catheterization in the neck on the sheep was observed, and the postoperative evaluation was carried out according to the pain performance and grading standards of the experimental animals. The results showed that central venous catheterization through the external jugular vein had little harm to the sheep; blood sampling and infusion could be repeated within 7 days after installation; the sheep behaved normally, the blood vessels at the catheterization position were normal, and the sheep’s appearance, diet and drinking, behavior and clinical manifestations were normal. There was no significant difference in the 6 blood routine indexes measured before and after operation（P＞0.05）. Cervical central venous catheterization did not cause pain and suffering to the 3 experimental animals, all were up to grade one. The results suggested that in the experiments related to frequent blood sampling or continuous intravenous administration of sheep, the application of central venous catheterization technology had a good effect.