This paper reports a combined experimental and numerical investigation of the pyrolysis characteristics of coal, biomass, and coal–biomass blends. Coal and straw were grounded and pressed into spherical particles with diameter of 8mm, and blended coal–straw particles were prepared through mixing pulverized coal and straw before pressed into particles. Sample particles were suspended in the center of a single-particle reactor system and devolatilized under different temperatures. The analysis of the time history of the residual mass of particles of coal, straw, and coal–straw blends suggested an absence of synergistic effect between the coal and the straw. In addition, a one-dimensional, time-dependent particle model; based on the chemical percolation devolatilization (CPD) and bio-CPD models; was developed to simulate the pyrolysis of coal and straw particles. The model predictions agree will with the measured data. An extended CPD model was proposed to explain the co-pyrolysis characteristics of coal–biomass blends. Encouraging agreement was found between the predicted and the experimental results of pyrolysis of coal–straw blends.