The invention discloses a flow-adjustable denitration catalyst wear strength testing device and a testing method, which are used for detecting the wear strength of a denitration catalyst testing platform. The testing device comprises a comparison bin, a testing bin, a feeder, a dust remover, an induced draft fan, a flow meter, a first branch pipe, a first adjusting valve, a first flow meter, a second branch pipe, a second adjusting valve and a second flow meter. The comparison bin, the testing bin, the dust remover and the induced draft fan are sequentially connected, the first branch pipe is connected with the comparison bin in parallel, the second branch pipe is connected with the testing bin in parallel, the first adjusting valve and the first flow meter are installed on the first branch pipe, the second adjusting valve and the second flow meter are installed on the second branch pipe, and the flow meter is connected to an inlet pipeline of the comparison bin. And a feeder is connected to the pipeline between the comparison bin and the test bin. The device can simulate the wear condition in the actual catalyst operation, controls the flow passing through the comparison sample and the test sample to be consistent and to be a predetermined value specified in the test standard, and is high in test result reliability.