Abstract: In order to provide a theoretical basis for production of biomass solid fuel，optimal processing parameters of hot pressing solid fuel from agricultural and forestry wastes of Sophora japonica，begonia and sunflower were found.Effects of particle size，moisture content，pressure and temperature on density of solid fuel for hot pressing of Sophora japonica，begonia and sunflower were studied by single factor design.At the same time，Taguchi method was used to analyze optimal shaping conditions of Sophora japonica，begonia and sunflower solid fuel and primary and secondary order of influence of each factor on fuel density.Results showed that optimum conditions of solid fuel forming of Sophora japonica and begonia were：particle size 0.63～1.25 mm，moisture content 5%，temperature 130 ℃，pressure 100 MPa.Optimum forming conditions of sunflower solid fuel were particle size 0.16～0.63 mm，moisture content 6%，temperature 140 ℃，pressure 120 MPa.Under optimum conditions，density of solid fuel of Sophora japonica，begonia and sunflower were 1.153，1.111 and 1.108 g/cm3，respectively.Particle size，moisture content，temperature and pressure had significant effects on density of solid fuel of three materials.Contribution of moisture content to solid forming density of Sophora japonica，begonia and sunflower was 69.06%，69.15% and 53.72%，respectively，which was much higher than that of other factors.Pressure（18.42%，11.99% and 33.27%）was the second.Contribution rate of temperature（7.54%，9.47%）of Sophora japonica and sunflower was higher than that of granularity（0.67%，2.01%），while that of begonia（2.67%）was lower than that of granularity（12.13%）.Water content was main factor that affected solid fuel shaping of Sophora japonica，begonia and sunflower.In actual production of biomass fuel，attention must be paid to the control of water content.