A rapid and facile one-step microwave-assisted hydrothermal approach was developed for the synthesis of diethylenetriamine (DETA)-functionalized graphene oxide decorated with Fe3O4 nanoparticles. This DETA-modulated magnetic graphene oxide (Fe3O4@DETA@GO) was used as a heterogeneous base catalyst for the Knoevenagel condensation. The composite demonstrated outstanding catalytic performance with easy recovery and reusability. [GRAPHICS] .