In order to study the influence of the preparation conditions of needle coke on the performance of lithium-ion batteries, the for⁃mation of semi-coke were studied during the thermal polycondensation reaction of coal tar pitch, and the morphological structure of thepolymerized products was characterized by polarized light microscopy and X-ray diffraction spectroscopy (XRD), focusing on the effectsof temperature, time and pressure on the polymerized products during the polymerization of coal pitch. The effect of temperature, time andpressure on the structure of the polymerized products was investigated. The experimental results shows that the temperature has the mostobvious influence on the reaction, and when the temperature is lower than 430 ℃ , the reaction can not further coke the product for a lon⁃ger time. When the temperature is 440 ℃ , the structure of the polymerization product can be controlled by time and pressure, and thestructure of the polymerization product is fine grains or mosaic structure of fine grains and coexistence of coarse grains. Comparing the elec⁃trochemical data of the polymerized product after charring and graphitization under different pressure, it can be seen that the condition ofpressure 2 MPa has the highest charge/ discharge specific capacity, the charge specific capacity is 219 mAh/ g and the discharge specif⁃ic capacity is 268 mAh/ g. After graphitization of 2 800 ℃ and 50 cycles, the specific capacity is 331 mAh/ g and the retention rateis 98%.