Transition-metal carbides, nitrides or carbonitrides (named as MXenes) are a novel type of two-dimensional (2D) materials with the features of traditional 2D materials but more variable chemical compositions. MXenes and related materials have raised more and more research attention and been extensively explored for different applications. In this work, we developed a novel method to synthesize magnetic MXene composites (Ti3C2-MNPs) for the first time through a one-pot route, which relied on the incorporation of Fe3O4 nanoparticles into Ti3C2 nanosheets via thermal treatment. The potential utilization of these Ti3C2-MNPs for catalytic degradation of organic dyes through advanced oxidation processes (AOPs) were also evaluated in details. We demonstrated that Fe3O4 nanoparticles with size about 5 nm could be anchored onto Ti3C2 with well dispersed state. The catalytic degradation results demonstrated that Ti3C2-MNPs possess extremely high degradation efficiency towards different organic dyes under optimal conditions. The electron spin resonance (ESR) spectra identified that both hydroperoxyl radicals (•OH) and superoxide radicals (•O2-) radicals were involved in the degradation process. This work reported a novel one-step method for fabrication MXenes based multifunctional composites, which show extremely high efficiency for AOPs. This method could also be extended for fabrication of many other multifunctional composites for various applications.