Thermoplastic starch compounds were prepared from cassava starch, glycerol, and tartaric acid by the twin-screw extruder. Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated the formation of ester bonds during starch modification through absorption peaks at characteristic wavelengths of C=O bonding and C–O bonding. Biodegradable polymer films fabricated from thermoplastic starch (TPS) and polybutylene adipate terephthalate (PBAT) by blown film extrusion process. Scanning electron microscopy (SEM) images showed that when using modified thermoplastic starch (MTPS), the material showed a more homogeneous structure. Besides, this study also selected the optimal content of tartaric acid as a compatibilizer, screw speed, and talc powder content used in the blend when determining the tensile properties and melt flow index (MFI) of the material.