Objective To observe the changes of liver and kidney function and coagulation parameters before and after acute fatty  liver (AFLP) plasma exchange (PE) in pregnancy. Methods The clinical data of 55 patients with AF treated with PE in  our hospital from January 2008 to January 1818 were retrospectively analyzed. The clinical symptoms, signs, liver and  kidney function, coagulation parameters and adverse reactions were analyzed before and after treatment. Results After  replacement, the levels of ALT, AST, TBIL, BUN, Cr, DBIL, NH3 and LDH were lower than those before replacement,  and the ALB level was higher than that before replacement (P<0.05). There was no significant difference in BUN level  (P>0.05). The levels of PT, APTT, WBC and D-II were lower than those before replacement, and the levels of FIB and  AT-III were higher than those before replacement (P<0.05). There was no significant difference in PLT level (P>0.05).  The incidence rate was 5.45%, which was significantly lower than 29.09% after treatment (P<0.05). Conclusion PE  can effectively improve liver and kidney function and blood coagulation function in patients with AFLP, and it is safe  and worthy of further application.