Objective To discuss the function of respiratory exerciser tri‐ball in pulmonary rehabilitation (PR) patients with chronic obstructive pulmonary disease(COPD) .Methods Prospectie case‐control study was used in COPD patients ,the patients were randomly divided into three groups ,60 COPD patients (group A) using respiratory exerciser TRI‐BALL ,58 COPD patients (group B) using traditional pursed lips ventral breathing training ,and 58 COPD patients(group C) using general internal medicine treatment .Results Group A :compared with before breath training ,the increases of FEV1/FEV1 predicted (% ) and MVV/MVV predicted (% ) and the decrease of quality of life score (QOL) were statistically significant after breath training (P<0 .01) ,but not for FEV1/FVC(% )(P>0 .05) .Group B :compared with before breath training ,the decrease of QOL was statistically significant (P<0 .01) ,but not for FEV1/FEV1 predicted (% ) ,MVV/MVV predicted (% ) and FEV1/FVC (% )(P>0 .05) .Compared with control group after breath training ,the increases of FEV1/FEV1 predicted (% ) and MVV/MVV predicted (% ) and the decrease of quality of life score (QOL) were statistically significant in group A (P<0 .01) .Compared with control group after breath training , the decrease of quality of life score (QOL) were statistically significant in group B (P<0 .01) ,but not for FEV1/FEV1 predicted (% ) and MVV/MVV predicted (% ) (P>0 .05) .Compared the changes of pulmonary function test(PFT) index and QOL between group A and B ,the increments of FEV1/FEV1 predicted (% ) and MVV/MVV predicted (% ) were statistically significant in group A(P<0 .01) ,but not for QOL(P>0 .05) .Conclusion It is useful to improve the pulmonary function and quality of life in patients with COPD using respiratory exerciser tri‐ball .It is more effective than traditional pursed lips ventral breathing training ,due to the equipment is very small ,cheap ,easy to quantify training and convenient for household use ,it is worth to be popularized in primary hospital .