A simple, green, and efficient mechanical activation-assisted esterification (MAE) technology was developed for the preparation of cellulose acetate butyrate (CAB), which was used as film-former for pearlescent coating. In addition, CAB was also prepared by a traditional liquid phase esterification (LPE) method for comparing the structures and characteristics of the CABs prepared by these two technologies. H-1 and C-13 NMR confirmed that CAB was successfully produced, and the degree of substitution of acetyl and butyryl groups was also calculated. The crystal structure and molar mass of the CABs prepared by MAE and LPE methods were dissimilar, ascribing to different reaction systems and characteristics. FTIR, SEM, and transparency analyses were used to investigate the chemical structure and surface characteristics of CAB films, and appearance, glossiness, rub resistance, and ethanol resistance measurements were carried out to investigate the surface and wear characteristics of CAB/pearlescent coating films. The results indicated that the surface and wear characteristics of the films based on MAE- and LPE-prepared CABs were similar to the same reaction time, and the interfacial adhesion and compatibility among components significantly affected the characteristics of the films.