The present invention discloses a microbial culture medium and a cultural method. The culture medium comprises a combination of strong acid-weak alkali salts and strong alkali-weak acid salts so that pH value thereof can be regulated and controlled in a stable and suitable range by itself, thus decreasing or eliminating an operable regulation on pH value via an external device in fermentation process and a risk of contaminations resulted from it in fermentation process as well, accordingly greatly improving the controllability and stability of the fermentation process. Meanwhile the ammonium salts acting as strong acid-weak alkali salts can be used as a nitrogen source to replace yeast cream to realize a decreased amount of nitrogen resource of high price, therefor sharply reducing the cost of the culture medium.