The invention discloses power adjustable secondary circuit energy consumption simulation test apparatus and method. The apparatus comprises a vapor generator simulation device which is connected with a plurality of condensation devices; communication between each condensation device and the vapor generator simulation device can be switched; each condensation device is connected with a water supply device which communicating with the vapor generator simulation device; a pressure stabilizing device is arranged between each condensation device and the corresponding water supply device; and the pressure stabilizing device communicates with all the condensation devices and all the water supply devices as well. The test apparatus and method can realize rapid and accurate regulation of the power of a secondary circuit, and realize the simulation of the whole secondary circuit system. The test apparatus has low cost, ensures the test accuracy, has high operability, is convenient to realize, and provides a whole solving scheme of secondary circuit system test simulation for overall simulation test systems of nuclear reactors.