Abstract: Diagenesis control the porosity evolution, with symbolic meaning, it is very important for the exploration of the oil and gas. The carbonate of middle-lower Permian of Wuwei-Chaohui area in Anhui province widely and well developed, and the organic matter is very rich. So many years the work is focused on strata, paleontology and sedimentary facies, little on diagenesis. Microscopic examination shows that the studying area mainly develop dissolution, dedolomitization, pressure solution, tectonic rupture four types of destructive diageneses and micritization, compaction, cementation, dolomitization, silicification, recrystallization six types of Constructive diageneses. Compared with the C-O isotope analysis results, this area included marine(shallow marine platform and deep sea slope), meteoric(vadose and phreatic zone) and burial mainly three types of diagenetic environment, developing different diagenesis respectively. Marine environment: mainly micritization(shallow marine platform) and the first type of silicification(deep sea slope); Burial environment: mainly compaction, pressure solution, dolomitization, the third type of selective silification and late recrystallization; Meteoric environment: cementation(including drusy isopachous rim cement, drusy cement and coaxial accretion cement, belonging to phreatic zone, gravity-type cement and crescent cement, belonging to vadose zone), dissolution, early recrystallization, dedolomitization and the second type of silicification. Except for rich organic matter, the studying area has high porosity, the highest is up to 2%-5%, mainly developed in the pressure solution of Chuanshan and Qixia Formation, also in the silicon members and silicon highly contained limestone of Qixia Formation, excellent connectivity and rich organic matter make it the ideal place for generation, storage and migration of the gas and oil. Therefore, there is great theoretical and strategical significance for the further geological study, predicting and explorating the gas and oil in studying the diagenesis of the carbonate of middle-lower Permian of Wuwei-Chaohui area in Anhui province.