Simple Summary: Clustered regularly interspaced short palindromic repeats (CRISPR) ribonucleoprotein (RNP)-mediated precise genome editing can modify a specific targeted gene to establish cell models and improve animal traits, thus playing a significant role in animal breeding. However, the efficiency of precise gene editing is low, which limits its widespread use. To overcome this problem in porcine cells, we used small molecules to improve the efficiency of CRISPR RNP-mediated precise genome editing in porcine fetal fibroblasts (PFFs). We demonstrated that a single small molecule including L-189, NU7441, SCR7, L755507, RS-1, and Brefeldin A increased the efficiency of homology-directed repair (HDR) during precise gene editing in PFFs, respectively. These results provided methodological support for the establishment of an efficient and precise gene editing system in pigs. The aim of this study was to verify whether small molecules can improve the efficiency of precision gene editing using clustered regularly interspaced short palindromic repeats (CRISPR) ribonucleoprotein (RNP) in porcine cells. CRISPR associated 9 (Cas9) protein, small guide RNA (sgRNA), phosphorothioate-modified single-stranded oligonucleotides (ssODN), and different small molecules were used to generate precise nucleotide substitutions at the insulin (INS) gene by homology-directed repair (HDR) in porcine fetal fibroblasts (PFFs). These components were introduced into PFFs via electroporation, followed by polymerase chain reaction (PCR) for the target site. All samples were sequenced and analyzed, and the efficiencies of different small molecules at the target site were compared. The results showed that the optimal concentrations of the small molecules, including L-189, NU7441, SCR7, L755507, RS-1, and Brefeldin A, for in vitro-cultured PFFs' viability were determined. Compared with the control group, the single small molecules including L-189, NU7441, SCR7, L755507, RS-1, and Brefeldin A increased the efficiency of HDR-mediated precise gene editing from 1.71-fold to 2.28-fold, respectively. There are no benefits in using the combination of two small molecules, since none of the combinations improved the precise gene editing efficiency compared to single small molecules. In conclusion, these results suggested that a single small molecule can increase the efficiency of CRISPR RNP-mediated precise gene editing in porcine cells. [ABSTRACT FROM AUTHOR]