The present invention relates to a hydrogel formulation for delivering probiotics including a hydrogel, probiotics and zwitterionic buffer as an active ingredient, a composition for delivering probiotics comprising the same and a method of preparing the same, which adjust and maintain the internal pH of the hydrogel even in the gastric juice environment, thereby increasing the survival rate of the probiotics in the gastric juice and improving the delivery rate to the large intestine, by further adding zwitterionic buffer capable of maintaining pH to the hydrogel encapsulated with probiotics.