The invention discloses an external hanging type lifeboat self-balance device and relates to the technical field of self-balance devices. The external hanging type lifeboat self-balance device comprises a left motor and a right motor which are arranged on the two sides of a lifeboat correspondingly; each of the left motor and the right motor drives a propeller to rotate to provide anti-rollover torque for the lifeboat; and the left motor and the right motor are both controlled by a control system. According to the external hanging type lifeboat self-balance device, working personnel on the lifeboat can provide the anti-rollover torque for the lifeboat during operation to maintain the balance state of the lifeboat.