Objective To explore the effect of pre-filled catheter flushing device on the sealing of venous indwelling needle. Methods One hundred and sixteen patients with venous indwelling needle were assigned into observation group, in which pre-filled catheter flushing device was used to seal the needle tube and another 109 with venous indwelling needle as control group, in which the needle tube was sealed with 50U/mL heparin saline.The two groups were compared in terms of blockage of the tube, phlebitis, catheter-associated infection, indwelling time of the needle and time for nurses to seal it.Results The rates of blockage of catheter, phlebitis and catheter-associated infection of the observation group were all lower than those of the control group.The indwelling time of the needle was significantly longer than that in the control group.The time for nurses to seal the catheter was significantly shorter than that in the control group(all P<0.05). Conclusion Pre-filled catheter flushing device can reduce complication rate and improve working efficiency of nurses.