The invention relates to a spatial ultrahigh-speed maneuvered target detection method based on RMDCFT (
Radon-Modified Discrete 
Chirp-
Fourier Transform). According to the method, firstly, modification is carried out based on the conventional 
Radon-
Fourier transform method by using 
prior information of spatial target motion parameters, searching is carried out in a known target 
motion parameter range, and thus, target echo signals are extracted along the motion trajectory of a target; meanwhile, modification is also carried out based on the conventional MDCFT method, transform 
processing is carried out on the extracted target echo signals, and thus, the 
estimation on the 
frequency modulation rate of the target can be obtained; 
secondary phase of echoes is compensated based on the 
estimation, coherent accumulation is carried out on the target echo signals, and target detection is realized. The method has no need of predicting or estimating the 
fuzzy number of speed of the target and is applicable to the circumstances of limited CPI (
Coherent Processing Time) and low 
signal-to-
noise ratio; 
simulation results are compared with 
processing results of MTD, 
Radon-
Fourier transform, FRFT (
Fractional Fourier Transform) and RFRFT (Radon-FRFT) detection methods, experimental results show that the method provided by the invention can be used for effectively detecting the target when the CPI is limited and the 
signal-to-
noise ratio is relatively low, and thus, the effectiveness of the method provided by the invention is proved.