To explore the scattering characteristics of aerosol particles in the near infrared band, the optical scattering characteristics of two hypothetical structures having mixed core-shell particles and the same aerosol particles in black carbon and sulfate aerosols are investigated by using discrete dipole approximation. A core-shell particle model with black carbon as the core and ammonium sulfate as the shell is constructed to simulate the extinction efficiency factor, scattering efficiency factor, absorption efficiency factor, asymmetry factor, and single scattering albedo of the particles at several incident wavelengths (875, 1020, 1640, and 2000 nm) in specific incident directions with varied effective particle sizes. The numerical results show that the extinction, scattering, and absorption efficiency factors of mononuclear shell particle, two-core cluster particle, and three-core cluster particle initially increase and then decrease with an increasing effective particle size at the same incident wavelength. In addition, the differences in the scattering and extinction efficiency factors of the three particles are less than 10%. With an increase in the number of nuclear particles, the radius of the particle structure increases, and the peak of the efficiency factor shifts backward. At the four different wavelengths, the asymmetry factor of the multi-nucleated cluster particles is 0.1777, 0.1960, 0.2900, and 0.3131 larger than that of the mononuclear shell particles on average, and the average difference between the asymmetry factors of the two types of multi-nucleated particles is 0.096. At the same effective particle size, the single scattering albedo of mononuclear shell particles is higher than that of multi-core particles; the larger the wavelength, the more distinct is the difference. The results are useful for further analyses of the optical scattering characteristics of complex atmospheric aerosol particles and monitoring of pollutants and climate.