Abstract: Start with microscopic characters of reservoir,through various experimental analysis,the following conclusions can be drawn:The rock in Fei xianguan formation of Pu guang area is mainly grain and granule dolomite;The reservoir space is mainly pore(dissolved pore,cave,etc.),The fracture doesn't develop on the whole¹.The sedimentary environment of the reservoir of this area is innate condition for its formation.The sedimentary environment dominate development and distribution of the reservoir;diagenetic reconstruction is crucial for reservoir formation,Large-scale tectonic movements lead to a kind of long-term diagesis and change with multiphse and multitype,which transform the previously primary pore dominated shoal facies deposit into secondary pore dominated reservoir,meanwhile,with these preferable preservation conditions,the current distributional features were formed.