This　paper　presents　method　that　applies　information　entropy　to　ascertain　index　weight,　researches　the　fundamental　principle　of　grey　decision-making,　analyses　factors　that　influence　building　construction　projects　biding　assessment,　and　creates　its　mathematic　model.　Furthermore,　this　paper　offers　a　scheme　of　bidding　assessment　to　prove　the　accuracy　and　objectiveness　of　grey　decision-making.