At present, sommelier is a popular profession in China. You can consult Xiangyi Wine Education, a well-known sommelier training institution in China. The sommeliers have ESW training courses, ISG sommelier courses in the United States and WSET sommelier courses in the United Kingdom. You can apply for any one according to your actual situation, which is recognized internationally and domestically. Senior sommeliers earn more than 10,000 yuan a month and have rich wine knowledge and tasting skills.
No national certification. Only commercial certification.
There are sommelier training institutions in China, and after taking the exam, they will frequently issue certificates of corresponding levels. The higher the level, the richer the knowledge.
If you are a beginner, you'd better attend the ESW junior sommelier course elsewhere. I suggest you have a look.