The utility model provides a safety early warning system for an unearthed well. The device is used in cooperation with a hoisting mechanism. The hoisting mechanism comprises a walking guide rail and ahoisting piece. The hoisting part walks on the walking guide rail; the hoisting part can do lifting motion relative to the walking guide rail so as to enter the unearthed well or leave the unearthedwell; the unearthed well safety early warning system comprises a warning unit, the warning unit comprises a switch piece and a warning piece, the switch piece is in control connection with the warningpiece, the switch piece is installed on a walking guide rail and located on a sliding path of a hoisting piece, and the hoisting piece can trigger the switch piece to enable the switch piece to openthe warning piece; and the warning piece is arranged in the unearthed well. The unearthed well safety pre-warning system is used in cooperation with the hoisting mechanism, when the hoisting mechanismneeds to run to the position above the unearthed well and descend into the unearthed well, the pre-warning system can give an alarm in advance to warn workers in the unearthed well to be away from adangerous area, and safety is greatly improved.