How to change a business visa to a work visa in Sudan?

This business visa cannot be directly converted into a work visa.

If you want to work in Sudan, you must first apply for a "work permit" from the Sudanese Ministry of Labor, and then apply for a visa from the Sudanese Embassy in China with a work permit and an invitation letter. You must register with the immigration office within three days after entering the country, then apply for a labor permit, take part in a physical examination, apply for residence, and go through tax payment procedures and exit visas when leaving the country.