Abstract: in order to explore the effect of calcium oxide on the catalytic pyrolysis characterstics of dfferent rank coas.the changes of the pyolysispreducts ditobution and the char structre were analzed based on Inmner Mongo ia Xilinguoe linte and Ningia Shizuis han anthracte were cariedout with a fived bed reaco.B)means of X.ray difiraction( XRD) and Fourier ranstom infrared specroscopy( FTIR).the variance of mcvocrytallinestructre aihatic stroctre,aromatizaion and oxygen-eniched eficiency of char prepared by pyrolysis oflignie and anthraiie under different temperatures before and afer addtion of cactum oxide were investigatedThe reseach resuts showed that the h2 cumulative yield of 2%CcaO added in ingnite at soo '℃ was the lagestreaching 39.11 m L/g. The Co cunmulatve yield of coasample with cacium oxide was greater than that of without calciun oxide in igh temperature pyrolysis stage.compared ith the adition of cactomn oxc e.the te mperture had a greater ifuence on the aromatic layer spacing and the diamer of the aromaticlayer.The value of ignte char aromatic layer stack height and the layer number increased gradcually with the adding of calciun oxide at oo ℃C.but anthracite char was on the contrary.The stuctural devaion degre of graptitizaton ofthe miecocrytalline structure of char prepared by pyrolysisof lignte and anthracie with the aditon of calcum oxide was higher than that of the char without the adtion of calcun oxide. The alighatic structure,aromatzation and oxygen-enrched eficiency infrared stucture parameterso lgntecharwas geneall highe than that of anthractchar.At high temperature,the degree of the condensation reaction was increased, and the conversion rate of the char was enhancedwith the adition of CaO, which led o the aromatzation parameters increased.The CO groups conmtent in raw oal was rare, and the Co groups wvas generated through reacion between the cacumn oxidepromoted aromatic ring cracking under high temperature and CO2, which led to oxygen-enriched effiency in char increased gradually