Abstract: A wearable device includes a case and a detection module. The case includes an inner casing and an outer casing. The inner casing includes a main body and a lateral wall. The main body is an annular structure. The lateral wall is disposed on a lateral side of the main body. The main body has a first installation area, a second installation area and a third installation area. The outer casing is disposed around the inner casing and abuts against the lateral wall, and the outer casing has a first opening. The detection module is disposed inside the case. The detection module includes an energy storage unit, an information transmission unit and an optical identification assembly. The energy storage unit is located on the first installation area. The information transmission unit is located on the second installation area. The optical identification assembly is located on the third installation area.