In the premise of cognition, open-theft theory makes no importance of the secrecy. This theory takes existing truth as a premise to adopt circular thinking, takes the foreign theory for granted to be assumed, and interprets penalty gap subjectively. So, in epistemology, there is deficient for the necessity of establishing the theory. In the arguments of the theory, it inappropriately uses literal interpretation, historical interpretation and comparative interpretation. It is not perfect in establishing the boundary of theft crime and distinction with robbery and other crimes of property. Therefore, it is questionable for the rationality and feasibility to construct open-theft theory in methodology. The theft theory should be reassessed, so as to maintain and develop the traditional theory of secret-theft.