The pyrolysis of Shenmu coal with three physically mixed additives (USY zeolite, CaO, K2CO3) was studied in a quartz tube reactor at a heating rate of 5 degrees C/min from room temperature to 600 degrees C for 15 min. Adding all three additives significantly increases the fraction of light components in tar while decreasing the total tar yield. The yield of light components in the tar had the highest increase from 9.5 to 11.1 wt % on daf coal by adding 1 wt % USY zeolite. The GC/MS analysis of the tar shows that the contents of both phenol and alkyl-phenols have the largest increase with the addition of USY zeolite. The C-13 NMR analysis of chars indicates that the increase of total phenol content in the tar is attributed to the catalytic cracking of aromatic oxygen carbon in coal structure. The cracking effect of USY produced more CH radicals that lead to the alkylation of phenols in tar to form more alkyl-phenols and the formation of C-1-C-4 hydrocarbons to release. The effect on formation of phenols followed the order USY > K2CO3 > CaO.