The present disclosure provides a catalyst for preparing lactic acid and derivatives thereof, comprising at least one of metallic compounds MXn, wherein M is selected from Na, K, Mg, Ca, Sr, Ba, Al, Ga, In, Sn, Sb, Bi, Cr, Mn, Fe, Co, Ni and Zn, and n is an integer of 1 to 6. The present disclosure further provides a method for synthesis of lactic acid and derivatives thereof, wherein at least one raw material including carbohydrates, at least one alcohol, at least one of the aforesaid catalysts and at least one solvent are heated to react to prepare lactic acid and derivatives thereof.