The invention discloses a large caliber heat meter test bed capable of checking multiple meters. The large caliber heat meter test bed comprises a pipeline bracket, a meter clamping pipe section and a protection cover; the large caliber heat meter test bed is characterized in that: an air cylinder is hung out of the meter clamping section; a sliding wheel is arranged on the protection cover; the protection cover is made of organic glass; a guiderail where the sliding wheel can glide is arranged on the pipeline bracket; when the meter is clamped, the meter clamping pipe section matched with the meter to be tested is selected; the meter clamping pipe section is placed on the pipeline bracket; a water inlet pipe section hole and a water outlet pipe section hole of each heat meter can be judged according to the water flow direction marked on the heat meter; the heat meter to be tested is arranged on the test bed according to the water flow direction arranged in a calibrating device; the meter clamping pipe section is connected with the corresponding pipe section hole of the heat meter; the heat meter and the meter clamping pipe section can be clamped by opening an air cylinder reversing valve on the pipeline bracket; the heat meter to be tested and the meter clamping pipe sections can be clamped in turn according to the method; and the protection cover is glided to the heat meter to be tested. The meter clamping machine has an in-place detection function, and after the meter is clamped completely, an in-place detector transmits signals to an upper computer.