Nano-Mg(OH)2, with low biological toxicity, is an ideal nano-carrier for insecticidal protein to improve the bioactivity. In this work, the adsorption features of insecticidal protein by nano-Mg(OH)2 have been studied. The adsorption capacity could achieve as high as 136 mg/g, and the adsorption isotherm had been fitted with Freundlich model. Moreover, the adsorption kinetics followed pseudo-first or -second order rate model, and the adsorption was spontaneous and exothermic process. However, the high temperatures are not suitable to adsorption, which implies that the temperature would be a critical factor during the adsorption process. In addition, FT-IR confirmed that the protein was adsorbed on the nano-Mg(OH)2, the Zeta potential analysis suggested that insecticidal protein was loaded onto the nano-Mg(OH)2 not by electrostatic adsorption but might by intermolecular forces, and the circular dichroism (CD) spectroscopy of Cry11Aa protein before and after loading with nano-Mg(OH)2 was changed. The study applied the adsorption information between Cry11Aa and nano-Mg(OH)2, which would be useful in the real appilation of nano-Mg(OH)2 as a nano-carrier.