To solve the problem of the stealthy object detectionthe judging inequality of radar detection based on the bistatic MIMO radar equation was utilized to make a research on the radars detection coverage to stealthy object.Taking the F117A fighter as a typical stealthy objectthe detection area was divided by the grid splitting algorithm.By calculating the bistatic radar across section of the stealthy object at each pointthe object detection coverage for bistatic MIMO radar could be obtained.The relationship among the detection coveragethe baseline lengththe number of the transmitting antenna and phase coherent accumulation was determined by experiment.The experimental result shows that the bistatic MIMO radar is superior to the conventional bistatic radar on detection range to stealthy target.