Objective To investigate the effect of the preparation time of cold precipitation on the contents of blood coagulation factors and fibrinogen in fresh frozen plasma. Methods A total of 160 fresh frozen plasma samples were prepared from October 2018 to April 2019. According to the time of collection, the fresh frozen plasma was divided into 4 groups: 6-h group, 8-h group, 12-h group, and 18-h group, with 40 samples in each group. The fresh frozen plasma of four groups was prepared into cold precipitation, and the contents of FVIII and Fg, and the quality of coagulation factors in the cold precipitation were compared among the four groups. Results With the prolongation of preparation time, the content of FVIII decreased gradually, and the difference was statistically significant (P<0.05); the Fg contents in the cold precipitation prepared in different time periods were not statistically significantly different (P>0.05); the qualified rate of 6-h group was 97.50%, which was higher than that of the 8-h group (92.50%), 12-h group (80.00%), and the 18-h group (55.00%) (P<0.05). Conclusion The preparation time of fresh frozen plasma has great effect on coagulation factors in cold precipitation but no significant effect on fibrinogen, and the optimal time for whole blood preparation of fresh frozen plasma was 6-8 hours, and the maximum time should be less than 12 h.