The utility model discloses a supporting structure of a horizontal pump, and belongs to the technical field of fixing and supporting tools. The supporting structure comprises a first supporting part and a second supporting part, the first supporting part is connected to the driving end of the pump shell through a first cylindrical pin, and the second supporting part is connected to the non-drivingend of the pump shell through a second cylindrical pin. The cylindrical pin is used for replacing a connecting bolt to be connected with the pump shell; when the pump body is in a thermal shock working condition, the cylindrical pin is used for bearing shearing force generated by thermal expansion, the stability of the whole supporting structure is enhanced, and safe operation of the pump set iseffectively guaranteed.