The invention discloses a floating and expanding collaborative type dimethylbiguanide gastric retention tablet containing 500 mg of dimethylbiguanide. The dimethylbiguanide gastric retention tablet is prepared from 500 mg of the dimethylbiguanide, hydroxypropyl cellulose, polyoxyethylene, sodium carboxymethyl starch, a coloring agent and magnesium stearate. Aiming at different gastric retention time, a formula is further defined; the product is regular and stable in drug release, and can meet medical requirements of different patient groups; moreover, the drug release in vivo is stable, a slow release effect is good, and a dosage form that the retention time of the floating preparation in stomach is extended and the bioavailability is improved is basically achieved.