Abstract: Statistical multiple input multiple output (MIMO) optimal detector structure is different for various types of targets, which is difficult to realize in practice. Statistical MIMO detector is designed, and a detector structure form is proposed here, which is easy to carry out. Echo signal models for MIMO radar and monostatic radar are investigated, and it is pointed out that MIMO radar echo is similar with monostatic radar echo for fast fluctuation target. Referring to monostatic radar detector structure for fast fluctuation target, it is suggested that statistical MIMO radar use the envelop detector followed by accumulator as the detector structure form. Based on the designed detector, detection performance is investigated for various types of targets. Theoretical and simulated detection performance curves are presented.