A joint locking device and crutch chair having the same, the joint locking device comprising a leg support unit (50) and a joint locking unit (60) the leg support comprises first leg sticks (51) and second leg sticks (52) respectively pivoted to the first leg sticks (51) the joint locking unit (60) comprises slide sticks (63) disposed on the first leg sticks (51) and enabling the sliding thereof relative to the first leg sticks (51), and locking blocks (65) disposed on the second leg sticks (52) corresponding to the slide sticks (63), each locking block (65) having a rotating shaft, a slide surface (652) using the rotating shaft as a center of circle, and a locking surface (653), a distance therefrom to the rotating shaft being less than the radius of the slide surface. The joint locking unit can switch between a locked position and an unlocked position in the locked position, the slide sticks are embedded between the locking surfaces and the first leg sticks to allow the first leg sticks and the second leg sticks to be fixed relative to each other in an unlocked position, the slide sticks are disengaged from the locking surfaces and linearly contact the slide surfaces to allow the first leg sticks to be pivotable relative to the second leg sticks, thus improving convenience and safety when using the crutch chair.
