Disclosed are an integrated electro-hydraulic steering actuating unit and a control method thereof, wherein an externally inputted control signal controls a rotation direction and a rotational speed of a bi-directional servo motor, and the bi-directional servo motor drives a protruding direction and a protruding speed of an actuating cylinder. The control valve block assembly is used for maintaining the movement position of the oil cylinder when the two-way servo motor is stopped, and can be used for dissipating heat from the oil returning side oil to the closed oil tank when the oil cylinderis extended, so as to reduce the temperature of the oil. The control valve block assembly is capable of limiting the working pressure of the actuating cylinder when the temperature or load of the actuating cylinder changes suddenly, and is used for setting the maximum working pressure of the bidirectional gear pump, limiting the output power of the bidirectional gear pump, and preventing the bidirectional servo motor from being overloaded. The control valve block assembly can realize the communication between the two chambers of the actuating cylinder to be in the floating working state, whichimproves the safety of the integrated electro-hydraulic steering actuating unit under the emergency working condition.