Gene therapy studies have been of great importance in the elimination of genetic diseases, and the capability of the CRISPR/Cas9 genome editing technique to correct genetic defects has shown great promise. As DNA-based Cas9 nuclease delivery is preferable because of its low cost and higher stability, effective vector-based CRISPR/Cas9 administration is urgently needed. Here, we used the multicellular organism Caenorhabditis elegans to optimize the polymer-mediated DNA delivery system to generate mutants with CRISPR/Cas9. Toward this end, the cationically quaternized polymer of POEGMA-b-P4VP (POEGMA-b-QP4VP) as a carrier of CRISPR/Cas9 components was first synthesized, followed by the formation of plasmid DNA-polymer complex called polyplexes. 1H NMR, Zeta-Sizer, Scanning Electron Microscopy (SEM) analysis, and gel retardation experiments confirmed the polyplexes formation, including pRF4 (Roller) and sgRNA dpy-10, which were then incubated with C. elegans. The polymer-mediated delivery system facilitated the generation of transgenic Roller animals and heritable Dumpy mutants with CRISPR/Cas9. Our study for the first time demonstrated optimized administration of CRISPR/Cas 9 components to C. elegans.