hello, My baby also has 倒流, thats "acid Reflux" in english. He used to projectile vomit almost all of his feed. Dont worry, as long as the baby's weight is gaining well, he will grow out of it when he get older. My baby hasnt projectile vomit anymore when he was 3 months old, but he is still on "Gaviscon" -- added into the milk to stablise stomach acid so that the milk and acid wont come back up. Although he stop vomit, but he used to cry and scream like mad the minute i put the bottle into his mouth because he learned that drinking the milk makes his acid and milk come back up and that hurts him. He is getting better with the medication and i hope once he start soild, everything will be fine.
Try Dr Brown's bottle, that may reduce the amt of air he swallow but to be honest, i dun think it help much for reflux baby like mine, but as a mom, i just try everything to make him feel better lor.