A new Fe3O4/Mo-MOF (metal–organic framework) magnetic nano polymer was synthesized in one step and Ultrasound assisted. Fe3O4/Mo-MOF magnetic nano polymer was characterized by XRD, SEM, EDX mapping BET, VSM, and FT-IR. The results of the structure confirmation revealed that the ultrasonic method had created unique properties in the Fe3O4/Mo-MOF magnetic nano polymer, and its biological and catalytic applications were investigated. A new pyrano[2,3-d]pyrimidines derivative was synthesized using the catalytic activity of Fe3O4/Mo-MOF magnetic nano polymer in a three-component reaction involving malononitrile, aldehyde derivatives, and barbituric acid derivatives with Fe3O4/Mo-MOF magnetic nano polymer as a magnetic catalyst. In the antimicrobial activity of Fe3O4/Mo-MOF magnetic nano polymer: Antimicrobial properties on gram-positive, gram-negative, and fungal strains based on MIC, MBC, and MFC value. The results of catalytic and biological studies proved that nanoparticles have unique properties attributed to their structure and synthesis method. [ABSTRACT FROM AUTHOR]