Based on the method of T-matrix, a detailed comparison of the distribution of light scattering Muller matrix elements with scattering angle on the polydisperse model, the monodisperse model and the equal-volume-sphere model of fractal structure of smoke particles is produced by flaming n-heptane, under the laser wavelength of 300, 633 and 800 nm respectively. The results show that scattering light could reflect the characteristics of the fractal structure of smoke particles and the distribution characteristics of primary particles in smoke particles when λ is equal to 300 nm, then the light scattering characteristics of fractal structure of polydisperse model and monodisperse model become identically when λ is equal to 633 nm, meanwhile, the light scattering characteristics of three models about the smoke particles produced by flaming n-heptane tend to be consistency when λ is equal to 800 nm.