Currently, various active capsule endoscopes have been developed to overcome the disadvantages of passive locomotion. Most of them are driven by electric motor or other actuators that need more energy, which will raise temperature and result in potential dangers. The high temperature will not only hurt the intestinal wall and tissue, but also affect the performance of electronic device embedded. In this paper, we focus on the thermal analysis of a novel active capsule endoscope called 鈥渋nternal force-static friction capsule robot (capsubot)鈥? The thermal distribution of the capsubot is calculated with the Finite Element Analysis (FEA) tools and the results are verified by experiments. Medical data on allowable temperature is referred and 43掳C is selected as the thermal threshold of biological safety for the small intestine. The results show that the temperature of the whole capsubot is below 41掳C, thus the capsubot is safe for human and the components embedded can work normally.