The embodiment of the invention discloses a robot tool switching anti-drop device which comprises a circuit control module and a gas circuit control module; the circuit control module is composed of tool detection sensors which are used for detecting whether detection tools are put in place or not and are arranged below tool placement frame tables respectively and a chuck electromagnetic valve which is connected to a chuck through a safety relay which is connected in series in a circuit in a manner of connection of the chuck electromagnetic valve and the safety relay; the gas circuit control module is composed of pneumatic travel control valves which are arranged at the middle parts of the corresponding tool placement frame tables and are mutually connected in series; and the pneumatic travel control valves are connected with a chuck cylinder through a one-way control valve which is connected with the pneumatic travel control valves. The invention aims at providing the robot tool switching anti-drop device which prevents the chuck from dropping on the aspects of the circuit and a gas circuit from the physical level.