If the Japan study visa renewal is refused, will it have any impact if I return to my country and switch to a work visa?

Yes. Although the study visa and the work visa are in different fields and will not interfere with each other, due to the previous experience of being rejected for the study visa, the Japanese Immigration Bureau will more strictly review the applicant's qualifications and conditions when applying for a work visa again. This will increase the difficulty and uncertainty of the application, so if the Japan study visa renewal is refused, it will have an impact on changing to a work visa after returning to the country.