The present invention belongs to the radar target detection technology field, and discloses a distributed radar heterogeneous signal level fusion object detection method. The method comprises: arranging a distributed radar system comprising N local radar stations and a fusion detection center; constructing the local detection statistics of each local radar station; arranging the false alarm probability pf of the distributed radar system; calculating the signal to noise ratio weight coefficient of each local radar station according to the corresponding local detection statistics and the false alarm probability of the distributed radar system; arranging a fusion decision threshold, performing signal to noise ratio weighting of the local detection statistics of the N local radar stations through the fusion detection center, and obtaining the fused detection statistics; and if the fused detection statistics is larger than the fusion decision threshold, determining that a target is detected, and determining the detection performance of the target.