Abstract: A type of supercritical carbon dioxide truncated cone cavity heat receiver was designed and developed for the solar energy disk concentrator. The optic-thermal model of the cavity heat receiver was established, and the optic-thermal characteristics of the cavity heat receiver were analyzed by Monte Carlo ray tracing method. Based on the related theory, the thermal boundary conditions were introduced as the input parameters to import into Ansys Fluent software. CFD simulation was carried out to study the optical characteristics and flow heat transfer characteristics of the cavity heat receiver. The outlet temperature, pressure drop, optical efficiency, thermal efficiency and losses of heat convection, radiation and conduction were obtained under different inlet temperatures（100-200 ℃） and different solar radiation intensities（400-1 200 W/m~2）. Results show that the optical efficiency of the cavity heat receiver remains basically unchanged under different solar radiation intensities. The influence of solar radiation intensity on the thermal efficiency of cavity heat receiver is not significant. The higher the inlet temperature of the working fluid is, the lower the thermal efficiency of the cavity heat receiver is. In the heat losses of cavity heat receiver, natural convection heat loss is the largest, followed by radiation heat loss and heat conduction heat loss.