Generally, no—not without a license. Under Hong Kong law, airsoft guns are classified as "Strategic Commodities". Their import/export is controlled by the Trade and Industry Department (TID).
Do not attempt to bring an airsoft gun in luggage without prior authorization. Violations can lead to seizure, fines, and prosecution. If you believe you have a valid reason, contact the Hong Kong Trade and Industry Department well in advance to inquire about the application process.