The invention discloses a gas cargo system for a CNG safe and efficient transport ship. The gas cargo system comprises a hull, as well as a gas storage unit, a matched pipeline system, a corresponding control unit and a servo mechanism which are limited in the hull. The gas storage unit comprises a gas bottle set arranged in a closed cabin and vertically distributed along the hull. The upper ends of gas bottles extend out of the closed cabin through upper end plug assemblies. The matched pipeline system is arranged above the closed cabin through the upper end plug assemblies and controlled pneumatic valves and connected with or disconnected from the gas bottles. The control unit, an auxiliary manual control component and a random detection and display component of the control unit are arranged on the two sides of a circulation channel above the closed cabin. Bottle bodies of the gas bottles are arranged to be separated from a pipeline and control system, the gas bottles start to be arranged from the bottom of the hull, the tops of the gas bottles penetrate out of a cabin cover through cabin outlet pipes, the bottle bodies are arranged in the closed cabin, the pipeline and the control system are arranged above the cabin cover, and the transport safety of the CNG ship is improved.