The evaluation of thermochemical characteristics and the development of kinetic model for pyrolysis of waste biomass are more challenging. In this study, the mass losses, intermediates evolved and products formed during pyrolysis of waste wood biomass were determined by coupling DSC/TGA-DTG/GC-MS/FTIR to improve the understanding of conversion processes and decomposition characteristics. The improved non-isothermal kinetics method was proposed by introducing the function of mechanisms, the activation energies and pre-exponential factors were estimated iteratively by regression to enhance modeling accuracy. The results indicated the gases of CO, CO2, CH4, H2 and the liquids of N-containing organics, esters, ketons and carboxylic acids were the most dominated products evolved. The pyrolysis of waste wood biomass could be divided into three phases, and with the increase of heating rates, the caloric requirement for pyrolysis was greatly increased. The random nucleation and one-dimensional diffusion predicted accurately the main (second) and third phases in the pyrolysis of waste wood biomass and waste camphor presented lower activation energies than waste bamboo. Display omitted •Pyrolysis of waste wood is studied by DSC/TG-DTG/GC-MS/FTIR.•Mass loss and energy requirement of pyrolysis are determined by DSC/TGA-DTG.•Gases and liquids of pyrolysis are analyzed by FTIR, GC-MS.•Improved kinetics method is derived to enhance the accuracy of model.