This study presents a conceptual design of a 200 MW laser Inertial Confinement Fusion (ICF) reactor blanket, referring to fusion reactor technologies. The blanket employs a dual-coolant structure consisting of supercritical CO₂ (S-CO₂) and liquid lead-lithium (PbLi). Transient and steady-state coupled models are established to calculate the temperature distribution and variations within the blanket. The implosion of the pellets is computed using MULTI-IFE. The nuclear heat coupling part is based on the Monte Carlo program OpenMC and self-programmed heat transfer models to calculate the blanket’s structure, cooling, and tritium production. The research findings indicate that the nuclear heat coupling model can complete preliminary calculations and analysis of the blanket. Periodic transient loads cause oscillations in the temperature of the first wall surface, but the temperature inside the blanket eventually converges to the steady-state calculation results. The reactor size significantly affects temperature reduction and oscillation effects, but it still requires xenon to flat radiation power peak. Both tritium production and energy export from the blanket are influenced by the reactor cavity size and the size of the breeding zone. Under the 200 MW operating conditions, it shows that a 3 m radius and a 0.25 m breeding zone size best meet the requirements.