The invention provides an implementation method for removing high-strength boulders inside a grooving hole of a deep foundation pit. The implementation method includes cutting-grabbing-sucking and comprises the following steps of: step (1) fixing equipment; step (2) moving and regulating the equipment until precise positioning is realized; step (3) cutting; step (4) grabbing and sucking, namely controlling a cutting motor to drive a hydraulic cutting telescopic arm to retract a stretching arm after the boulders is cut completely; subsequently controlling a grabbing motor to drive a grabbing telescopic rod to downward stretch an L-shaped grabbing knife to make preparations for grabbing the boulders; afterwards by using a controller, controlling a rolling disc stepping motor to drive a rolling disc to rotate so as to drive a rolling shaft to rotate, and realizing up-and-down movement of a sucking disc by virtue of rotation of the rolling shaft; when the L-shaped grabbing knife makes contact with the boulders, controlling reversed-Y-shaped sucking claws positioned at the bottom of the sucking disc to make contact with the boulders (10) by using the controller; subsequently controllinga sucking disc to move an air pump to input high-pressure air into a main air passage to make sure that the high-pressure air reaches the reversed-Y-shaped sucking claws so that the reversed-Y-shapedsucking claws are closely attracted to the boulders by virtue of the pressure of the high-pressure air; and step (5) moving up the boulders to fulfill the task.