Objective To observe recycle homorheology index of two autologous blood recover machines in orthopedic operation , including maximum deformation index (DImax) ,aggregation index(AImax) ,osmotic fragility ,hematocrit(Hct) ,hemoglobin(Hb) , blood electrolytes and pH value ,the changes of in vivo Hct ,Hb ,blood electrolyte and pH value after the autotransfusion to provide references for rational clinical use of cell salvage .Methods Seventy‐six patients were randomly divided into group A (CATS) and group B (Cell Saver) ,38 cases in each group .Autologous test of DImax ,AImax ,osmotic fragility ,Hct ,Hb ,blood electrolytes ,pH value and Hct ,Hb ,osmotic fragility ,pH value of patients before and after autotransfusion ,24 h after operation ,used to determine the in vivo salvaged were measured .Results DImax of group A were lower than that of group B with no difference(P<0 .05);AImax of both groups had no different(P>0 .05) ,but was lower than the reference value .RBC osmotic fragility curve shifted to the right in group A ,each index was significantly lower than its reference value(P<0 .05) .The in vivo Hct ,Hb ,K+ of group A were significantly higher than that of group B ,Na+ level of group A was lower than of group B ,each index had significantly difference with its reference value(P<0 .05) .pH value of both groups was slightly alkaline .The in vivo Hct ,Hb ,K+ ,Na+ level and pH value of both groups had no difference at the point of before and immediately after autotransfusion and 24 h postoperatively ,there were no statistically difference(P>0 .05) .The in vivo Hct of both groups after autotransfusion were significantly higher than before(P<0 .05) .Conclusion The hemorheology index and quality of salvaged blood acquired from these two cell salvage systems in orthopae‐dic operation have no obvious differences .The function of these two kinds of cell salvage systems is safer and reliable .