The present invention provides an interference prevention control device of a work machine, wherein the interference prevention control device is capable of limiting movement of a cab based on a position of a tool and thereby preventing interference of the cab with the tool as well as improving the work efficiency of the work machine. A cab position sensor for detecting a position of a movable cab, as well as a boom angle sensor and an arm angle sensor for detecting a position of a tool at the distal end of the work equipment, are connected to a controller. Solenoid-operated directional control valves for limiting movement of a cab lifting cylinder are disposed in pilot passages of a spool of a pilot-operated control valve, and the solenoids of the solenoid-operated directional control valves are connected to the controller. Based on the positional relationship between the position of the cab (cab interference area) detected by the cab position sensor and the position of the tool detected by the boom angle sensor and the arm angle sensor, the controller controls movement of an actuator of the cab by means of the solenoid-operated directional control valves so as to prevent interference between the cab and the tool.