The invention discloses an elbow and knee joint traction rehabilitation robot and a traction angle adjusting mechanism thereof. The robot comprises a supporting component, a bed body, fixing strap quick release mechanisms, a traction rope, the traction angle adjusting mechanism, a gentle force control mechanism, a computer control and acquisition system and a human-computer interaction interface. The traction angle adjusting mechanism comprises a pull rope displacement sensor. The elbow and knee joint traction rehabilitation robot has advantages that precision control of elbow and knee joint traction angle and traction force can be realized, comprehensive rehabilitation treatment of a patient can be realized, and rehabilitation time of elbow and knee joint diseases is greatly shortened.