Using the gas-phase chemical reaction kinetics software CHEMKIN PRO， the basic reaction chain of the detailed chemical reaction kinetics model of n-butanol was numerically analysed， so as to find out the main reaction paths and intermediate products involved in the low-temperature and high-temperature reaction phases of n-butanol fuel. Based on the semi-decoupling methodology， the small molecule mechanism of C1/CO/H2 was taken as the kernel for n-butanol， and coupling the main mechanisms of low-temperature reaction and the transition reaction from large molecules to small molecules， a new reduced chemical reaction kinetic model of n-butanol with 70 species and 150 reactions was developed， which was validated by the tested data of basic reactors， such as the one-dimensional laminar flame speed and shock tube. The results show that the developed new reduced mechanism of n-butanol can both accurately calculate the ignition delay time， and reasonably predict the evolution trend of the laminar flame speed.