To address the slow decomposition of maize straw returned to the field under winter low-temperature conditions in Northeast China, microcosm incubation experiments were conducted at three temperatures (20°C, 4°C, and ?20°C) to compare the effects of three cold-adapted nanozymes (Cu-Fe3O4 NPs, ND1; FeEP NPs, ND2; and ε-MnO2, ND3), two microbial agents (Phanerochaete chrysosporium, JZ1; and Aspergillus niger, JZ2), and the combined treatment of ε-MnO2 and Phanerochaete chrysosporium (LY) on maize straw degradation. After 28 days of incubation at 20°C, 4°C, and ?20°C, the degradation rates of the maize straw under the ND3 treatment reached 27.08%, 8.58%, and 1.83%, respectively, representing increases of 41.30%, 87.27%, and 144.44% compared with the CK, and exceeding those of all other treatments. Meanwhile, the lignin content of the ND3-treated straw decreased from the initial value of 13.10% to 5.94% (20°C) and 8.09% (4°C), significantly lower than the CK values of 7.96% (20°C) and 8.57% (4°C), indicating that ND3 effectively promoted lignin degradation. The ND3 nanozyme significantly enhanced the activities of enzymes related to straw degradation at all tested temperatures, with the most pronounced increases observed in laccase and lignin peroxidase activities at 4°C, demonstrating strong catalytic potential under low-temperature conditions. Overall, these findings suggest that metal oxide nanozymes have the potential to catalyze straw degradation under low-temperature conditions, offering a promising approach for the low-temperature degradation of straw in cold regions such as Northeast China.