Abstract: An expandable capsule endoscope includes a shell, a membrane and a bag. Inside the shell are a first compartment and a second compartment, and the membrane is disposed between the first compartment and the second compartment. The bag is connected outside the shell. There is a first substance and a second substance respectively disposed in the first compartment and the second compartment. When the membrane is ruined and broken by a heating energy, the first substance and the second substance react to produce a gas filling the bag. The expandable capsule endoscope is applicable to examine an organ with wider diameters and advantageous to capture images of the organ thus providing better reliability and utility.