5-Bromo-7,7-dimethyl-7H-benzo[a]fluorine was prepared from 1-Bromonaphthalene in 63.12% yield. The synthetic process of intermediates 2-(1-naphthalenyl)benzaldehyde, 7-methyl-7H-benzo[c]fluorene and, 7-dimethyl-7H-benzo[c]fluorene were optimized. The optimum conditions were as follows: In the synthesis of 2-(1-naphthalenyl)benzaldehyde, when the amount of catalyst Pd(dppf)Cl2 was 3.0% and reaction temperature 40℃, the yield was 96.8%. In the synthesis of 7-methyl-7H-benzo[c]fluorene, when the amount of catalyst Amberlyst 15 ion-exchange resin was 0.6%, reaction temperature 110℃ and reaction time 4 h, the yield was 95.4%. In the synthesis of 7-dimethyl-7H-benzo[c]fluorene, when n(methyl 4-methylbenzenesulfinate)/n(7-methyl-7H-benzo[c]fluorene)=2.5:1 and reaction temperature 40℃, the yield was 91.0%. The product was characterized with 1HNMR and ESI-MS.