When the leveling ship works to position,the uneven geological thin hard layer penetrating is the main factor to affect the safety.If the legs don’t locate in bearing stratum when the leveling ship ballasts,the puncture engineering accident might happen.Combined with the domestic and foreign relevant materials and the actual geological situation of Hong Kong-Zhuhai-Macau bridge construction site,the stability checking calculation and analysis research for the leveling ship’s legs penetrating the hard layer was carried out.The results reveal that leveling ship’s legs ballasting and penetrating through composite foundation,they may puncture the foundation.When the leveling ship’s legs penetrat into soft layer with thin hard layer,the stability coefficient should be calculated to reveal whether there will be a puncture.The pre-control measures had been put forward for leveling ship penetrating thin hard layers.