To reveal the reservoir effectiveness of Wushi 17X oilfield, the diagenetic evolution history of reservoir is analyzed by means of casting thin section identification, carbon and oxygen isotope analysis, scanning electron microscopy observation, combined with burial evolution history, thermal evolution history and underground water solution activity, Reservoir has undergone alkaline-acid-alkaline evolution process, diagenetic evolution sequence has undergone early siderite and dolomite cementation, medium-term feldspar and debris mineral dissolution, secondary quartz increase and kaolinite formation, gypsum cementation, late quartz dissolution, gypsum dissolution, iron calcite cementation, siderite recrystallization. On the basis of the diagenetic evolution history, combined with the transformation relationship between facial porosity and porosity, the inversion and denudation of porosity were carried out through compaction correction, thus the actual porosity evolution curve in geological history was established. Curve study shows that the loss of porosity due to compaction is greater than that due to cementation, and the increase of porosity due to dissolution is the main factor for later hydrocarbon accumulation. The relationship between pore evolution history and oil and gas filling history shows that the reservoir porosity is medium during oil and gas filling period, which is conducive to oil and gas filling, and the later period is more saturated due to the contribution of dissolution. The matching relationship between pore evolution history and hydrocarbon accumulation makes the evaluation of reservoir effectiveness more accurate.