Abstract: During marine seismic exploration process， the position of air-guns in water must keep a safe distance with the hull. Without doing so， air-gun source will cause shipboard facilities and equipment severely shaking， which affects the safe operation of ship. Even worse， it may cause damage to the hull. With consideration of the relationship between seawater pressure pulse and the impact pressure towards the ship and combination of the air-gun source wavelet model which stimulates the near-field source wavelet， the safe distance between the hull and the air-guns can be calculated. Research results show that the safe distance of total capacity 150 in³ G gun， 300 in³ coherent G guns and 760 in3 coherent G guns are 3.90 m， 6.57 m and 9.13 m， respectively， according to peak value of near-field wavelet simulated by air-gun source wavelet model. It can be known that the distance between the place of air-guns and the hull should be greater than a safe distance in order to avoid large vibration of the hull or equipment from damage and to ensure effective and safe marine seismic exploration．