My son (16 months) deliberately tries to vomit the food? We still haven't started solids and give hi

OT. If this is strictly a behavioral issue, there are occupational therapists who specialize in helping toddlers with these issues. Consult your pediatrician.
Need full evaluation. Normal, healthy babies do not "deliberately" try to vomit. A baby who is not eating solid food by 8 months must be fully evaluated by a pediatrician. He can refer the baby to a pediatric gastro-enterologist (specialist) if needed. Doctors will look for malformations in the gut between the mouth and the intestine, examine for neurological problems, and review the feeding techniques used by parents.