In this study, we developed an improved comprehensive pyrolysis scheme by modifying the bio-oil species and gas species fractions, increasing the carbon fraction in the char, and combining and changing the metaplastic decompositions for energy analysis. The two-fluid model (TFM) framework was used to simulate pyrolysis in a two-dimensional tubular reactor, and 10 g of 1500-μm-sized pinewood particles was used as biomass feedstock. Pyrolysis was performed at 400 °C−600 °C with an average heating rate of 115 °C/min. The improved scheme was evaluated against recent comprehensive pyrolysis schemes with respect to decomposition characteristics. The pyrolysis product yields and compositions predicted by the improved model accorded with experimental results. Moreover, the energy contents and distributions of pyrolysis products were successfully estimated, and the relative errors of bio-oil, gas, and char energies were 0.61%, 9.54%, and −3.76%, respectively. The energy distributions were more dominant influenced by the pyrolysis product yields than by the energy density.