Brand extension is one of the important brand strategies of enterprises. With the help of brand extension, enterprises can promote new products to the market at a lower cost and gain consumer recognition more easily. This article studies the impact of a brand’s cultural image on brand extension from a consumer perspective, that is, how global brands and local brands can extend their brands to gain consumer favorability more easily. The study found that global brands have high extensibility to adapt to the needs of consumers in different markets, which makes them more suitable for long-distance extension; local brands better suit to the unique needs of local consumers with lower extensibility, which means they are more suitable for near extension. The match between the brand’s cultural image and brand extension affects consumer attitudes by affecting their processing fluency of information.