The invention discloses a tool-blocking tool-dropping fault early-warning device for a circular disc type manipulator tool magazine, and aims to carry out early-warning for tool-dropping and tool-blocking faults of an existing numerical-control machine circular disc type manipulator tool magazine. The tool-blocking tool-dropping fault early-warning device comprises two early-warning units, wherein each early-warning unit consists of a color mark sensor, a beam, an alarm and a bracket. The tool-blocking tool-dropping fault early-warning device for the circular disc type manipulator tool magazine disclosed by the invention can comprehensively detect that screw joint between a shank and a blind rivet loosens, can detect screw joint looseness with different degrees between the shank and the blind rivet according to the needs, is suitable for circular disc type manipulator tool magazines of different models, shows flexibility and universality, can automatically operate for a long time under an unmanned monitoring state, can reduce labor intensity, exposes and arouses product faults, provides practical essential data for reliability evaluation of the circular disc type manipulator tool magazine, and also can be used for screening chain-plate circular disc type manipulator tool magazines.