The invention discloses a detection device and a detection method for cleaning the performance of a cleaning robot. A measuring panel is in a rectangular shape, four supports are installed on four corners of the measuring panel, four baffle plates are installed on four edges of the measuring panel, and a to-be-detected cleaning robot is arranged in a measuring initial area; a measuring device comprises a four high-precision cameras, the four cameras are installed on the supports on the four corners in a hinging manner through connecting rods, and the four cameras are collectively cooperated with one another to form a visual field covering the entire measuring panel; auxiliary accessories comprise obstacles put on the measuring panel and a dust distributor, and the dust distributor is provided with dust. The working environment of the cleaning robot is simulated by virtue of the dust distributor and various obstacles, the motion track of the cleaning robot is followed by virtue of the machine vision, and the coverage rate and cleaning rate of the cleaning robot are calculated by adopting the repeated coverage removal method; the cleaning amount performance and the coverage rate performance of the cleaning robot X are effectively and accurately detected.