A thermal simulation device is applied to a transaction-level designed chip which includes a plurality of intellectual properties. The thermal simulation device includes a plurality of thermal-aware transaction-level power model circuits, a simulator, a translator and a thermal emulator. The thermal-aware transaction-level power model circuits corresponds to the respective intellectual properties, and are configured to a corresponding power information for each of the intellectual properties, and dynamically adjusts the power information according to temperature information. The simulator is configured to generate the corresponding temperature information of the intellectual properties according to compatible information. The translator is configured to generate the compatible information which is compatible with the simulator. The thermal emulator is configured to trigger the simulator and transmit the temperature information to the intellectual properties.