Abstract: In order to reveal the regularity that friction heat formed in biomass cold briquetting can cause temperature change and use this regularity to design biomass molding machine, physical parameters such as average stress and equivalent velocity were defined to establish friction heat analytical model of biomass mould according to the characteristics of biomass cold and heat transfer theory. Numerical simulation experiment on heat friction formed in biomass cold briquetting was conducted. Compared with experiment results, the theoretical model results were reasonable. The temperature change regularity caused by friction heat in biomass cold briquetting was concluded, it was that after running 60 min the internal surface temperature of mold reached softening temperature of lignocellulose, at that temperature the quality of mold was improved. Also after running 240 min temperature of that tended towards stability and final temperature of that was from 115 to 125℃. By adjusting the kinds of raw material , mold material , mold structure, production rate and so on, the operating time to softening temperature of lignocellulose can be reduced and the quality of mold can be improved.