In order to investigate the pyrolysis gaseous product distribution,tar components, and the char crystallite structure of demineralized bituminous coal after the calcium and nickel ion were loaded with the ion exchange, impregnation and mechanical mixing methods, respectively. The pyrolysis experiments of Hexi bituminous coal were carried out with a fixed bed reactor. By means of scanning electron microscopy and energy dispersion spectrum analyzer (SEM-EDS), X-ray diffraction (XRD), nitrogen adsorption surface analyzer, the changes of physical and chemical structure of demineralized bituminous coal were investigated after calcium and nickel ion was loaded by ion exchange,impregnation and mechanical mixing methods. The results indicate that the pyrolysis reactivity changes occur mainly due to the state of active component was loaded by three different load methods. The light tar yields of H-EX-Ca, HIM-Ca and H-MM-Ca coal samples are 1.87%, 2.17% and 2.15% respectively, and the fraction of light tar (boiling point < 360 ℃) is 46.24%, 38.96% and 29.36% respectively.Compared with the load nickel ion, the effect of calcium loaded by ion exchange and impregnation on the catalytic cracking of heavy tar is stronger. The more uniform loads metal ion distribution, the less changes the crystallite structure parameters of the chars (average stacking height Lc,carbon crystallite site Laand interplanar spacing dm), therefore, it inhibits the progress of char graphitizing and increases the char gasification reactivity. [ABSTRACT FROM AUTHOR]