Flexible shape-memory polymers were synthesized by Pickering high internal phase emulsion (HIPE) polymerization and used to adsorb and separate tetrodotoxin (TTX) from an aqueous solution. SiO2 nanoparticles were used to stabilize the Pickering oil-in-water (O/W) HIPEs. We introduced imidazolium-modified bromobutyl rubber (IBR) with excellent mechanical properties and high viscosity into the emulsion system as the shape-memory monomer. The properties, such as shape memory and morphology, were characterized by various methods, and batches of static adsorption experiments were conducted to analyze the adsorption performance of SiO2@IBR on TTX. The characterization revealed that the SiO2@IBR had a porous structure and good shape memory. Thus, the combination of SiO2 particles and IBR prevented shedding of SiO2 and enhanced the mechanical and adsorption properties of SiO2@IBR. The results of the adsorption experiments indicated that the SiO2@IBR had good adsorption of TTX. Both the Langmuir and Freundlich models fitted the isothermal adsorption experiment process. The TTX adsorption capacity of SiO2@IBR was about 290.44 mg/g at 308 K. The fitting results of the pseudo-first-order and pseudo- second-order kinetic models showed that the adsorption process involved both chemical bonding and physical adsorption. After 10 adsorption and desorption experiments, the adsorption capacity of SiO2@IBR decreased less than 0.03％, indicating that it had good adsorption and regeneration performance.