A semidecoupling methodology for developing skeletal chemical kinetic models is presented and applied to construct an enhanced skeletal model for PRF (primary reference fuel) oxidation, which consists of 41 species and 124 reactions. The basic idea and the semidecoupling methodology are to consider the oxidation mechanism of alkane as two parts: a comprehensive part to describe detailed reaction processes of C0-C1 radicals and molecules as the 'core' and a skeletal part that couples the 'core' to control the ignition characteristics. Accounting for the major weakness in the existing skeletal models for PRF oxidation, the enhancement on the new skeletal model mainly focuses on the laminar flame speed and important species evolution while maintaining the precise ignition delay prediction of the previous models. The new PRF skeletal model is validated against various experimental data including shock tube, jet-stirred reactor, flow reactor, premixed laminar flame speed, and internal combustion engines over a wide range of temperatures, pressures, and equivalence ratios. The results show good agreement with the experimental data, indicating that the semidecoupling methodology and the new skeletal model are promising for various reactors and engine applications incorporated with a multidimensional computational fluid dynamics (CFD) model.