The work aims todetermine the TOC in biodegradable plastics for packaging by the combustion oxidation method. Samples with known inorganic carbonate fillers were treated with hydrochloric acidification and without acidification respectively, and the differential effect of eliminating the interference of inorganic carbonate by acidifying samples was studied. The combustion temperature was optimized by investigating and comparing at different temperature from the TOC results of thin-layer cellulose. Under the optimized conditions, calcium carbonate was used as the standard material for carbon content, and the actual sample of biodegradable plastics for packaging was quantitatively tested. The test measurements showed that the deviation between the measured value and the theoretical value of the plastic sample after acidification was only -1.22%～+1.42%, while the deviation between the measured value and the theoretical value of the plastic sample without acidification was +7.40%～+29.36%, which indicated that the test result after acidification was more accurate; Besides, the combustion and oxidation tests were carried out at 950 ℃～1 250 ℃ respectively, and the optimal combustion temperature was found to be 1 100 ℃; The standard calibration curve was protracted with calcium carbonate as the standard material. In addition, the results showed that the standard calibration curve had a good linear relationship in the range of 0.6 mg to 24 mg carbon content; Seven biodegradable plastic samples were tested, and the deviation between the measured TOC and the theoretical calculated value was between -4.26% and +3.47%. The study shows that the method is simple and has great linearity, high precision and accuracy. It is suitable for the determination of TOC in biodegradable plastics.