The invention relates to a glipizide calcium alginate gel micro pill and a preparation method thereof, belonging to the medical technical field. In the method, mixture solution of glipizide and alginic acid sodium salt is prepared, wherein, the glipizide and the alginic acid sodium salt can be mixed and then put into a solvent, or the glipizide is put into a solution of the alginic acid sodium salt solution; the ratio of the alginic to the alginic acid sodium salt is between 10 to 1 and 1 to 10(w/w), and the concentration of the alginic acid sodium salt is between 0.5 and 5.0 percent; the mixture solution is added to a solution of calcium chloride in the condition of stirring, and reacts for 1 minute to 72 hours; products are filtered, taken out, washed and dried to obtain the glipizide calcium alginate gel micro pill. The preparation method adopts a calcium alginate micro pill as carrier, prepares the glipizide calcium alginate gel micro pill by dropping method in one step, has simple process and low cost. The prepared micro pill is not dissolved in artificial gastric juice, thereby reducing the stimulus to stomach; and the micro pill has high entrapment rate and drug-loading rate, releases in artificial intestinal juice slowly, improves the effect of decreasing blood sugar and has good market prospect.