PBL teaching mode is a kind of emphasis on students' independent inquiry based learning approach, which is concerned withthe problem of inquiry and solution process, focusing on the cultivation of students' ability. The teaching mode is a new teaching mode basedon the problem and the students as the main body. The open and distance education students of economics as the research object, using the PBLmode of teaching, the results show that the effect of the teaching mode of PBL is obviously better than the traditional teaching mode is helpfulto improve the students' ability of autonomous learning, inquiry learning, acquisition, processing and use of statistical information, and theanalysis of the problem, the comprehensive ability to solve problems etc.. The PBL model of critical thinking training includes students'participation in the setting of goals and problems, group discussion cognitive activities and the reflection and evaluation of teachers and students.