It has a very broad prospect to use solid particles as the working medium in the solar collector of concentrated solar power generation system. The emissivity of a particle has an undeniable effect on the efficiency of a solid particle receiver. However, the spectral emissivity of a single particle at high temperature is rarely reported. In this work, an experimental method for measuring the spectral emissivity of a single particle at high temperature is established. This method is based on a self-designed heater, Fourier transform infrared spectrometer (FTIR) and a blackbody furnace. It can measure the spectral emissivity of a single particle at high-temperature of 500-900°C, and the test wavelength range is 2.5–25 μm. By measuring the spectral emissivity of 3–5 mm diameter particles, the influence of particle size on the emissivity was obtained. The expanded uncertainty of spectral emissivity of 3 mm SiC particles at 800°C is 1.380%.