Does the “high text disclosure” under the “low actual investment” of corporate digital transformation imply a bubble? How does textual information disclosure that exceeds the actual level of investment in digital transformation affect investors’ investment decisions? This paper uses data from A-share companies from 2006 to 2021 to explore the impact of the digital transformation disclosure of “talk more, do less” on stock mispricing. The findings show that such disclosure reflects the motives of companies to manipulate their market value. This kind of disclosure strategy is difficult for investors to identify in the short term, increasing stock mispricing and causing stock prices to deviate upwards from their fundamental values. Mechanism testing suggests that the disclosure strategy inflates investor sentiment, leading to stock mispricing. Further research reveals that: First, the phenomenon of “talk more, do less” in digital transformation disclosure may lead to stock mispricing across various segmented fields of digital technology. Second, high-quality audits, performance of independent directors, and good internal governance can suppress stock mispricing under the digital transformation disclosure of “talk more, do less”. This paper offers insights into the financial risks underlying corporate digital transformation disclosure and the governance of such risks.