The　blasting　fly-rock　poses　a　potential　risk　to　workers　at　the　blasting　site.　Considering　the　uncertainty　of　various　influencing　factors　of　the　risk,　this　paper　introduces　the　uncertainty　measurement　theory　to　build　a　pre-evaluation　model　of　blasting　safety　for　flyrock,　in　which　the　weight　and　identification　criterion　of　each　evaluation　index　are　determined　by　information　entropy　and　confidence,　respectively.　Then,　the　model　was　adopted　to　pre-evaluate　the　harms　of　blasting　fly-rock　in　an　earthwork　excavating　project.　The　case　analysis　shows　that　the　model　can　quantify　the　uncertainty　of　each　influencing　factor,　and　realize　objective　evaluation　of　the　risk　of　blasting　fly-rock.　The　research　findings　lay　a　solid　basis　for　reasonable　and　effective　control　of　the　harms　caused　by　blasting　fly-rock.　©　2018　Lavoisier.