By using the complex variable method, the problem of interface cracks between three-dimensional icosahedral quasicrystals and circular elastic inclusion under the action of a point heat source was investigated. Combined with the Schwarz analysis continuation principle, the generalized Liouville theorem and the singularity analysis of complex functions, the problem is transformed into a Riemann boundary value problem, and the general solutions of temperature and stress functions are obtained. As a special case, the solutions of the interface with a single crack are derived, and the analytic expressions of intensity factors at the crack tips are obtained. Numerical examples are given to analyze the effects of inclusion radius, point hot source intensity and coupling coefficient on thermal stress and stress intensity factors of three common composites. The current research not only provides theoretical guidance for the reliability design and optimization of quasicrystal composites but also contributes to a deeper understanding of the thermomechanical behavior of quasicrystal composites.