How to become an anesthesiologist?

First of all, you need to know that there is no such profession as "anesthesiologist"! The anesthesiologist is an anesthesiologist, not a technician, and the anesthesiologist is a clinician because anesthesiology is a subspecialty of clinical medicine, the same as internal medicine, surgery, pathology, imaging, etc. The anesthesiologist is a clinical doctor, not a technician.

That is to say, those who work in anesthesia are clinicians who need to be qualified as clinical practitioners. Anesthesiologists, like doctors in other disciplines, need to receive formal education in undergraduate or specialist clinical medicine or clinical anesthesiology, and after graduation to obtain the qualification of a licensed physician or assistant practitioner, and registered as an anesthesia specialist in the hospital before they can carry out clinical anesthesia work.

So, if you want to become an anesthesiologist, you first have to get a medical school's clinical medicine or special anesthesiology program, graduate with the corresponding degree, and then take the exam for a licensed physician or an assistant (the latter can only work in sub-county level medical units). It's no different than becoming a doctor in any other specialty.