Abstract: The existing transform methods of basic probability assignment to probability are widespread lack?of?objective criteria and with much subjectivity. A linear weighted probability conversion method is presented. First, the?normalized priori information?is selected as weight to eliminate?the subjective factors?in transformation; Then,?an?equation?is constructed based on?the principle?of?information conservation before and after the transformation; Finally,?an iterative solution method is given for transformational probability. The experimental examples show that?the?solving speeds are fast,?the transformational probabilities are reasonable, effective, and?consistent with?the awareness level of the event.