Abstract: As a class of fuzzy connectives with important application value in numerous fields, 2-uninorms have long attracted extensive attention from scholars in the field of fuzzy logic. This paper focuses on uninorms and 2-uninorms, and first provides sufficient and necessary conditions for two members in the class of uninorms U_\textlinc to be order equivalent. On this basis, further characterizations are carried out on the order equivalence of 2-uninorms whose underlying uninorms belong to U_\textlinc . The findings of this paper reveal the algebraic structural features of 2-uninorms from the perspective of order theory, and offer certain guidance for the practical application of this operator.