What should I do in Singapore if I want to study abroad or immigrate? I have no criminal record.

Contact the Singapore Police Department directly to apply for a certificate of innocence.

However, from 201010, the Singapore police stopped issuing innocence certificates to non-citizens.

You can find a lawyer to swear, and the affidavit can be directly used as a proof of innocence in some cases; If you can't, you need to get an affidavit, and then go to the Singapore police/Singapore embassy in various countries to collect fingerprints and apply for a power of attorney without a criminal certificate. The police will issue a criminal certificate.