An insulation assembly, comprising: an insulation pipe (120, 220) having a first end (120a, 220a) and a second end (120b, 220b) opposite to the first end (120a, 220a); an insulation umbrella group (130, 230) formed on an outer wall of the insulation pipe (120, 220); and an insulation base (140, 240) made of insulating material and connected to the first end (120a, 220a) of the insulation pipe (120, 220), wherein the insulation base (140, 240) comprises an insulation flange (141, 241) and an insulation connection tube (142, 242) wherein the insulation connection tube is configured to have various diameters, wherein the insulation connection tube comprises: a first tube portion located at the one end of the insulation connection tube far away from the insulation flange: a second tube portion located at the other end of the insulation connection tube adjacent to the insulation flange; and a third tube portion connected between the first tube portion and the second tube portion, wherein the first tube portion has a first constant outer diameter, the second tube portion has a second constant outer diameter larger than the first outer diameter, the third tube portion has a third outer diameter gradually changing from the first constant outer diameter to the second constant outer diameter, characterized in that, one end of the insulation connection tube (142, 242) is connected to the first end (120a, 220a) of the insulation pipe (120, 220), the other end of the insulation connection tube (142, 242) is connected to the insulation flange (141, 241). an insulation pipe (120, 220) having a first end (120a, 220a) and a second end (120b, 220b) opposite to the first end (120a, 220a); an insulation umbrella group (130, 230) formed on an outer wall of the insulation pipe (120, 220); and an insulation base (140, 240) made of insulating material and connected to the first end (120a, 220a) of the insulation pipe (120, 220), wherein the insulation base (140, 240) comprises an insulation flange (141, 241) and an insulation connection tube (142, 242) wherein the insulation connection tube is configured to have various diameters, wherein the insulation connection tube comprises: a first tube portion located at the one end of the insulation connection tube far away from the insulation flange: a second tube portion located at the other end of the insulation connection tube adjacent to the insulation flange; and a third tube portion connected between the first tube portion and the second tube portion, wherein the first tube portion has a first constant outer diameter, the second tube portion has a second constant outer diameter larger than the first outer diameter, the third tube portion has a third outer diameter gradually changing from the first constant outer diameter to the second constant outer diameter, characterized in that, one end of the insulation connection tube (142, 242) is connected to the first end (120a, 220a) of the insulation pipe (120, 220), the other end of the insulation connection tube (142, 242) is connected to the insulation flange (141, 241). a second tube portion located at the other end of the insulation connection tube adjacent to the insulation flange; and a third tube portion connected between the first tube portion and the second tube portion, wherein the first tube portion has a first constant outer diameter, the second tube portion has a second constant outer diameter larger than the first outer diameter, the third tube portion has a third outer diameter gradually changing from the first constant outer diameter to the second constant outer diameter, characterized in that, one end of the insulation connection tube (142, 242) is connected to the first end (120a, 220a) of the insulation pipe (120, 220), the other end of the insulation connection tube (142, 242) is connected to the insulation flange (141, 241).