Abstract: The preparation equipment for OBT combustion was developed, which was made of three parts including quartz glass tube, fixed and mobile furnace and condenser collecting unit. The sample weight is 40-100 g, the efficiency of combustion for OBT is 97.4%, and the water recovery is 94.4%. The equipment was applied for different biological samples collected from Sichuan Provice, such as plants and animals. The results show that the radioactivity is between 0.16-2.71 Bq/kg. The radioactivity in meat sample is high and the radioactivity in plant sample is low.