The sedimentography characteristics, types of reservoir space and distributional characteristics of physical property in Lower Triassic Feixianguan Formation reservoir in Yuanba area of Northeast Sichuan are researched comprehensively and a geological model of Feixianguan Oil Reservoir is built through abstraction and conceptualization of the sedimentary characteristics. The geological model reveals that the marine facies carbonate reservoir is well development in the sedimentary areas of platform margin which includes slope. reef and shoal sedimentary areas. Among them, the oil reservoir in the platform-margin shoal are well developed, and that in platform margin slope area ranks the second but reef in platform-margin area is not found developed. The 1st Member to the lower 2nd Member of Feixianguan reservoir belongs to slope facies and the upper 2nd Member to the 3rdMember is shoal facies. It is suggested that the oolitic shoal reservoir rock developed in the 1st and the 2nd Members are favorable to future exploration, especially the 2nd Member of porosity-fracturing reservoir that have good potential.