<p>DNA base editors are transformative genome editing tools that enable nucleotide conversions without inducing double-stranded DNA breaks, making them promising for correcting genetic mutations. Current base editors, however, are limited by fixed editing windows and constrained location of deaminases. To address these constraints, we develop a modular system termed Plug-in Base Editor (Plug-in BE), which dynamically programs deaminase positioning via integrating various epitopes and antibody-fused deaminases. This system expands the editing capabilities of base editors by optimizing deaminase’s spatial interaction with DNA, leading to improvements in efficiencies, window restrictions, and safety profiles. We validate Plug-in BE’s versatility and high fidelity in cancer gene therapy and zebrafish embryo editing, demonstrating its potential as a powerful and adaptable tool for basic research and therapeutic applications. This innovation can generate a series of base editors without extensive protein evolution, positioning Plug-in BE as a significant advancement in the field of genome editing.</p>