A facile and flexible approach is developed to fabricate bubble-propelled mesoporous micromotors carrying nanocatalysts for efficient water remediation. The micromotors are prepared by simply coating the hemispherical surface of Fe3O4-nanoparticle-containing mesoporous SiO2 microparticles with a polydopamine layer for decorating Ag nanoparticles, based on the versatile adhesion and reduction properties of polydopamine. The Fe3O4 nanoparticles can produce OH radicals from H2O2 for pollutant degradation via Fenton reaction, whereas the mesoporous SiO2 matrix provides large surface area with anchored Fe3O4 nanoparticles for improved degradation performance. Moreover, the Ag nanopartides can decompose H2O2 into oxygen bubbles for powering the movement of micromotors to further enhance the pollutant degradation. The micromotors that synergistically integrate these functions enable efficient degradation of pollutants, such as methylene blue demonstrated in this work, for water remediation. This approach offers a simple and versatile strategy for creating micromotors with flexible compositions and structures for applications in water remediation, drug delivery, and cargo transport.