Purpose: While oral PrEP has demonstrated efficacy, adherence remains suboptimal among adult MSM in China. Long-acting injectable PrEP (LAI-PrEP), such as Cabotegravir and Lenacapavir, offers a promise for closing this gap, but evidence on awareness and acceptability in Chinese populations is still limited. This study seeks to evaluate awareness and intention to use LAI-PrEP among MSM in China. Methods: We conducted an online cross-sectional study among adult MSM across China from November 2024 to February 2025. Participants who were recruited through community-based organizations and social media platforms completed a structured questionnaire measuring socio‑demographics, sexual behaviors, and health-related behaviors. Multivariable logistic regression was used to explore the correlates of awareness and willingness. Results: A total of 1022 eligible MSM with a mean age of 29.6 years (SD = 7.61) completed the survey. Overall, 321 (31.4%) reported awareness of LAI-PrEP, while 706 (69.1%) expressed an intention to use it. Three-quarters (75.0%) of the participants identified as gay, and about four-fifths (82.0%) disclosed their sexual orientation to others. The majority (97.3%) of the participants had ever tested for HIV. Multivariable logistic regression showed greater awareness among participants with postgraduate education (aOR = 1.92, 95% CI 1.06–3.52), monthly income > $1,110 (aOR = 2.26, 95% CI 1.40–3.73), self-identifying as gay (aOR = 1.52, 95% CI 1.06–2.21), having more than one casual partner (aOR = 1.61, 95% CI 1.05–2.49), and HIV testing (aOR = 3.58, 95% CI 1.21–15.40). Willingness to use LAI-PrEP was higher among participants with a college education (aOR = 1.56, 95% CI 1.02–2.39), higher income ($420–1,110: aOR = 1.66, 95% CI 1.11–2.49 > $1,110: aOR = 2.19, 95% CI 1.40–3.43), and having more than one casual male partner (aOR = 1.72, 95% CI 1.09–2.72).Conclusion: The substantial gap between awareness (31.4%) and willingness (69.1%) represents a critical implementation opportunity. Focusing on critical factors such as higher education, income levels, and sexual identity, public health campaigns can tailor their outreach efforts to engage individuals most likely to benefit from LAI-PrEP.