Can the school bus in Shenzhen carry students without a school bus permit?

You can't. The Interim Measures for the Administration of School Bus Traffic Safety in Shenzhen stipulates that schools and kindergartens should use motor vehicles with school bus licenses to carry students, otherwise they will be detained and fined, and formal students without school bus licenses shall not be used. When a school or school bus service provider applies for a school bus license, it shall submit a written application to the education administrative department of the people's government at the county level or at the municipal level with districts, and prove that it meets the requirements.