Abstract: Different separating technique, concentration technique and spray drying technique were investigated in this study in order to utilize animal blood effectively and optimize the preparation technique of plasma protein powder. First, the effects of different centrifugal speeds and times on the concentration of total plasma protein, hemoglobin residues and yield were studied.Besides, the effects of different ultrafiltration pressure and p H on moisture content, crude protein content and ash content of plasma protein powder were analyzed.Finally, the effects of different inlet temperatures and feeding rates on moisture content, protein content, extraction ratio and nitrogen soluble index of plasma protein powder were investigated.The results indicated that the best centrifugal condition was at 5000 r/min for 10 min.The best ultrafiltration condition was at 0.6 MPa airflow pressure, and the p H of plasma was 9.The best spray drying technique was under inlet temperature 150 ℃ and feeding rate 0.178 m L/s.After this optimization technique, the ash content of plasma protein powder decreased to 6%.The results can provide basic data and reference for the improvement of low ash plasma protein powder preparation technique.