A multifunctional oil gas energy-saving stove mainly comprises a housing, a heat insulation layer, a heat insulation layer cavity, a water tank, a heat exchange and circulating tubes. The heat exchanger, the water tank and a connecting tube between the exchanger and the water tank are functional structure parts, and also are high-efficiency and large-area heat exchangers, so a large amount of a raw material can be saved. While normal diner cooking and dish frying are carried out through using a boiler in the invention, waste heat is utilized to generate a large amount of hot water and a large amount of boiled water, and also generate a large amount of steam to steam buns, rice and dishes. The multifunctional oil gas energy-saving stove has a stove outside steaming or heating function. The waste heat hot water, the boiled water and the steam do not have pressures, so no matter how to operate, there will be no safety accidents. The body of the stove, the heat exchanger and the water tank are arranged in an integrated manner, so a kitchen can be neat and beautiful. The multifunctional oil gas energy-saving stove has the advantages of low system manufacturing cost, long life, high reliability, simple production technology, large-scale industrialized production, and wide market prospect.