Heat transfer is the critical process controlling the performance of heat extraction from hot dry rock (HDR) involved in enhanced geothermal systems (EGS). To facilitate the exploitation of EGS, this paper establishes a semi-analytical model for the flow and heat transfer of heat-carrying fluid in a parallel-fractured HDR reservoir. The temperature responses were obtained by a numerical Laplace inverse transform method. The computation results show that parallel fractures with infinite spacing can be simplified into multiple independent single-fracture models. It is found that the dimensionless outlet temperature of the parallel fractures is influenced by several dimensionless quantities (e.g., Fo, η, ξ and γ). Similar to that in a single fracture channel, the dimensionless outlet temperature shows an ”S-shape” time-varying profile over time consisting of an initial stage, a mid-stage, and a quasi-steady stage. The time scale of each stage depends on the fracture spacing and the transfer rates of main thermal processes in HDR, i.e., heat conduction rate in the rock, the convective heat transfer rate on the fracture surface, and the internal heat convection rate in the fractures.