An operational stability enhancing device for construction machinery, comprising: a plurality of cameras (10, 20, 30, 40, 50; 220) configured to capture surrounding images of construction machinery; a plurality of sensors configured to detect an obstacle located in a surrounding area of the construction machinery; a monitor (60; 240) configured to display the surrounding images of the construction machinery captured by the plurality of cameras (10, 20, 30, 40, 50; 220); an electronic hydraulic pressure control valve configured to control an output flow rate of a corresponding hydraulic system driving unit so as to correspond to a manipulation signal of a user manipulation unit of the construction machinery; a manipulation signal determiner configured to determine a current operation state of the construction machinery by receiving the manipulation signal of the construction machinery; an obstacle determiner configured to read from the camera the surrounding image of the moving path of the construction machinery when the manipulation signal determiner determines the operation state, compare the read image with the surrounding information obtained by the scanner, check whether the surrounding information is changed, and determine an existence of the obstacle; and a control signal generator configured to, in a case where a detected object is detected in a surrounding area of a moving path by the sensor, receive from the operator an input signal for determining whether the detected object is the operation target or the avoidance processing target when the obstacle is detected as a result of the determination of the obstacle determiner, and filter a current value of the manipulation signal, which disables the operation of the obstacle determiner when a signal corresponding to the operation target is generated, and which causes the corresponding operation command to be automatically delayed or stopped when the construction machines approaches the detected object when a signal corresponding to the avoidance processing object is generated; and a control unit (70; 280) configured to in a case where the detected object is an avoidance processing target, display an image of the captured detected object on a monitor through screen conversion or change the image of the captured detected object when the construction machines approaches the detected object. a plurality of cameras (10, 20, 30, 40, 50; 220) configured to capture surrounding images of construction machinery; a plurality of sensors configured to detect an obstacle located in a surrounding area of the construction machinery; a monitor (60; 240) configured to display the surrounding images of the construction machinery captured by the plurality of cameras (10, 20, 30, 40, 50; 220); an electronic hydraulic pressure control valve configured to control an output flow rate of a corresponding hydraulic system driving unit so as to correspond to a manipulation signal of a user manipulation unit of the construction machinery; a manipulation signal determiner configured to determine a current operation state of the construction machinery by receiving the manipulation signal of the construction machinery; an obstacle determiner configured to read from the camera the surrounding image of the moving path of the construction machinery when the manipulation signal determiner determines the operation state, compare the read image with the surrounding information obtained by the scanner, check whether the surrounding information is changed, and determine an existence of the obstacle; and a control signal generator configured to, in a case where a detected object is detected in a surrounding area of a moving path by the sensor, receive from the operator an input signal for determining whether the detected object is the operation target or the avoidance processing target when the obstacle is detected as a result of the determination of the obstacle determiner, and filter a current value of the manipulation signal, which disables the operation of the obstacle determiner when a signal corresponding to the operation target is generated, and which causes the corresponding operation command to be automatically delayed or stopped when the construction machines approaches the detected object when a signal corresponding to the avoidance processing object is generated; and a control unit (70; 280) configured to in a case where the detected object is an avoidance processing target, display an image of the captured detected object on a monitor through screen conversion or change the image of the captured detected object when the construction machines approaches the detected object.