Can I apply for a Hong Kong work visa after graduation?

Yes. HKUST(GZ)'s recent graduates who wish to apply to work in Hong Kong may be granted 24 months’ stay on time limitation only without other conditions of stay provided that normal immigration requirements are met.
For more details, please refer to the official policy on the Hong Kong Immigration Department's website: https://www.immd.gov.hk/hks/services/visas/IANG.html