This paper analyses the lender of last resort theory in Bernanke’s economic work The Federal Reserveand the Financial Crisis from the perspective of conceptual metaphors. It finds that the conceptual metaphormodel of the theory is mainly based on the Economy as a Machine and the Economy as an Organism. Based onthis, Bernanke reasoned that when a machine or organism has an internal problem, it needs to be repaired byan external force. This is projected onto the financial system as the need for central banks to artificially repairand bail out the financial system, which advocates government intervention and regulation of the financialmarket. Some scholars have related to Bernanke’s view, and they also reasoned the Economy as a Machine andthe Economy as an Organism. However, they believed that machines can repair themselves and organisms canregulate their internal order, advocating the dominant role of the market’s regulation. The analysis shows thatconceptual metaphors play a central role and reveal the cognitive basis in the construction of economic thought.It suggests that economic research should not be overly formalized, but should also pay attention to the mode ofconstruction of concepts in economic thought.