Based on seismic data, logging data, and analytical data of cores, cuttings and nature gas samples, the characteristics of the natural gas accumulation, key controlling factors and accumulation model of the natural gas accumulation of the central submarine canyon are studied and discussed. The results demonstrate that there is a large old submarine canyon along the axis of the central depression of Qiongdongnan basin and named the central canyon, which was formed from Late Miocene to Early Pliocene. The canyon is filled with multiphase turbidite sandstones, and those of which the average porosity ranges from 15% to 33% and permeability range from 11×10-3 to 971.3×10-3μm2 are high-quality reservoirs for natural gas. Mainly two kinds of traps developed in the canyon: the lithologic trap and the structural-lithologic complex trap. The natural gas bearing in the turbitide sandstones sources from the coal layers of the Yacheng Formation, and is coal-type one. Organic matter of the source rock are Type II2 with Type III，major in Type III. Thermal evolution of the source rock indicates that the hydrocarbon-generating potential of the source rock reaches its maximum in Late Miocene to Pliocene, and are presently in mature and highly-mature stage. The cetral depression of Qiongdongnan Basin is a high-pressure and high-temperature depression，with the average geothermal gradient of 4.2°C/hm to 4.6 °C/hm and pressure coefficients of 1.20 to 2.15. The diapirism occurring under the ventral canyon has generated effective channels for vertical and lateral migrating of the gas, which is the key factor for accumulation of the gas in the turbidite sandstones filled the central canyon.