The invention relates to an erecting insulation cabin and a sealing rain preventing method thereof. The erecting insulation cabin comprises an erecting part and a cabin cover, wherein the cabin covercomprises a left top cover, a right top cover, a left side cover, a right side cover, a left inner rear cover, a right inner rear cover, a left outer rear cover and a right outer rear cover; a first sealing structure is arranged between the left top cover and the right top cover; a second sealing structure is arranged between the left top cover and the left side cover; a third sealing structure isarranged between the right top cover and the right side cover; fourth sealing structures are arranged between the left top cover and the corresponding left inner rear cover, between the right top cover and the corresponding right inner rear cover, between the left side cover and the corresponding left outer rear cover and between the right side cover and the corresponding right outer rear cover respectively; fifth sealing structures are arranged between the left inner rear cover and the adjacent right inner rear cover, between the left inner rear cover and the adjacent the left outer rear cover, and between the right inner rear cover and the adjacent right outer rear cover respectively; overlap gaps of the first sealing structure, the second sealing structure, the third sealing structure,the fourth sealing structures and the fifth sealing structures do not intersect in space. The erecting insulation cabin has the advantages of simple structure and reliable sealing. The sealing rain preventing method has the advantages of simple process and good rain preventing effect.