The invention relates to the technical field of coolers, in particular to a sealing structure connecting a high-temperature cooler heat exchanging tube and a shell. The sealing structure comprises theshell, the heat exchanging tube, a sleeve, a sealing head and a tandem connection tube, wherein an intermediate water cooling channel is arranged in the shell. The intermediate water cooling channeldivides the shell into the shell outer wall and the shell inner wall, the heat exchanging tube is perpendicular to the intermediate water cooling channel and penetrates through the shell, the sleeve sleeves the heat exchanging tube, the sleeve is separately welded and fixed to the shell inner wall and the shell outer wall, one end of the sealing head is located between the heat exchanging tube andthe sleeve, and the tandem connection tube is connected to the other end of the sealing head. According to the sealing structure connecting the high-temperature cooler heat exchanging tube and the shell, an assembly type structure is adopted, effective sealing of gas and liquid of tube pass fluid and shell pass fluid during penetrating through the shell is realized, the seal reliability of the equipment is improved, and realization of rapid overhaul and maintenance of the heat exchanging tube is facilitated.