Objective To explore the preventive effect of pneumatic compression therapy combined with infrared irradiation against lower extremity deep vein thrombosis(DVT)in critically ill patients.Methods A total of 150 critically ill patients from January 2021 to January 2023 in the Intensive Care Unit,Quanzhou First Hospital Affiliated to Fujian Medical University were selected and divided into control group and observation group,with 75 cases in each group.The control group patients were treated with conventional rehabilitation measures combined with the boot-type intermittent pneumatic compression therapy device for intermittent inflation and compression therapy,while the observation group patients received the bioinformatic feedback infrared therapy besides the treatment in control group.The incidence of DVT,the average time for swelling and pain reduction,the average time for swelling and pain disappearance,total hospitalization time,the hemodynamic indexes of the lower extremities,coagulation indexes,D-dimer,the recurrence rate of swelling and pain,satisfaction with the rehabilitation,and therapeutic efficacy were recorded.Results After 3 months of discharge,the rate of post-discharge swelling and pain recurrence in observation group was 2.67％(2/75),obviously lower than 10.66％(8/75)in control group(P＜0.05).After 14 days of intervention,the lower extremity deep vein blood flow velocity and peak blood velocity of the two groups increased significantly as compared with those before intervention(P＜0.05),and those were greater in observation group than in control group(P＜0.05).After 14 days of intervention,the coagulation indexes(PT,TT,FIB)and D-dimer level were significantly lower or shorter in both groups as compared with those before intervention(P＜0.05);and observation group had shorter PT and TT,and lower levels of FIB and D-dimer than control group(P＜0.05).The average time for swelling and pain reduction,the average time for swelling and pain disappearance,and the total hospitalization time were shorter and the incidence of DVT was obviously lower in observation group as compared with control group(P＜0.05).The overall response rates of 14-day intervention in observation group vs control group were 97.33％(73/75)vs 88.00％(66/75)(P＜0.05).At the discharge,the satisfaction rates in observation group vs control group were 96.00％vs 85.34％(P＜0.05).Conclusion The combination of bioinformatic feedback infrared therapy and boot-type intermittent pneumatic compression therapy device for intermittent inflation and compression therapy can shorten the average time for swelling and pain reduction,the average time for swelling and pain disappearance and the total hospitalization time,enhance the hemodynamics of the lower extremities,improve the coagulation function and D-dimer level,and improve the satisfaction with the rehabilitation and clinical efficacy,worthy of clinical promotion.