The invention relates to an ultra-thin air conditioner of a shell type heat exchanger. The ultra-thin air conditioner comprises a machine body and a top plate. The machine body is provided with a fancavity, a centrifugal volute fan is arranged in the fan cavity. One side of the fan cavity is provided with an evaporator cavity, the evaporator cavity is provided with a shell type evaporator assembly, the two ends of the shell type evaporator assembly are fixed in the evaporator cavity through end heads, the shell type evaporator assembly is provided with a fin assembly, a long strip-shaped through groove is formed in the fin assembly, and a heat exchange main body is arranged in the through groove in a matched mode. The ultra-thin air conditioner of the shell type heat exchanger is high inpracticability, compact in structure, small in thickness and high in heat exchange effect.