To provide a self-traveling crushing machine which suppresses the damage of a detecting means for detecting the posture of a discharge conveyor, and can detect the posture of the discharge conveyor with stability.

The self-traveling crushing machine for crushing an object to be crashed. includes: right and left traveling devices 2; a crusher 20; the discharge conveyor 40 extending forward from between the right and left traveling devices 2 below a body frame 3; a lift cylinder 65 for lifting up and down the discharge conveyor 40 relative to the body frame 3; a bottom side pressure detecting means 96 for detecting the pressure of a supply conduit 94 connected with a bottom side oil chamber 65a of the lift cylinder 65; a posture determination section 92a for determining that the discharge conveyor 40 is in a working posture when a detection pressure power P1 of the bottom lateral pressure detecting means 96 exceeds a threshold value P1x set beforehand during the descending operation of the discharge conveyor 40; and an operation enabling section 92b for allowing the crusher 20 to operate only when the discharge conveyor 40 is determined to be in the working posture by the posture determination part 92a.