Aiming at the problem of small transmitting power and low target detectability of miniaturized space target detection radar,a weak target detection method suitable for miniaturized space target detection radar is proposed.Firstly,analyzing the received pluses which are dechirped.Secondly,applying the second-order Keystone transform to eliminate the range curvature,then the quadratic term of slow time is removed by estimating the acceleration of the target.Next,using the second-order Keystone transform again to compensate for the residual range walk.At the end,long time integration is performed for weak target detection,thus the signal to noise ratio is improved.In addition,a fast searching method of phase-coherent accumulation time agility is used to select different accumulation time in different detection ranges.Simulation analysis shows that the effectiveness of the proposed method is verified,and the simulation results and operation speed of two second-order Keystone transformation methods,sinc interpolation and CZT-IFFT are compared.