Abstract: Objective To investigate the effect of different values of the pressure P in poisoning functional constipation biofeedback training. Methods From April,2012 to October,2014,120 cases of patients with functional constipation in severe hospital diagnosis and treatment were selected. According to the pressure target P value(P1=10 mm Hg,P2=25 mm Hg,P3=35 mm Hg),divided into three groups,each 40 cases. Using pressure-mediated biofeedback training,ten times as a course of treatment,three groups of patients three courses. Clinical efficacy record three groups of patients,colon rectal pressure measurement results measured by experiment and. Results The results showed that,in P1 group,the total efficiency was 50. 00%,in P2 group,the total effectiveness was 77. 50%,in P3 group,the total efficiency was 40. 00%,the P2 group was significantly better than the P1 and P3 groups,the difference was statistically significant(P < 0. 05). Rectal pressure measurement show that in the first treatment,the three groups of patients anal resting pressure,reduced pressing pressure,bowel pressure was not statistically significant(P > 0. 05),after treatment,P2 patients anal resting pressure,reduced pressing pressure,defecation Pressure group were higher than P1,P3 groups,P2 group defecation pressure higher than P1 group,the differences were statistically significant(P < 0. 05). Colon through trial showed that before treatment,the number of cases discharged three groups of patients,the discharge rate was not statistically significant(P > 0. 05),after treatment,P2 number of cases of patients discharged,the discharge rate is higher than P1 group,P3 group,P2 group discharge number of cases,the discharge rate is higher than P1 group,the differences were statistically significant(P <0. 05). Conclusion In summary,biofeedback in the treatment of functional constipation curative effect is sure and in pressure P value is 25 mm Hg,the clinical efficacy in patients with the most significant and pressure of rectum and colon by experimental results,and the best,it is worth of clinical application.