Increasing integration time is a main approach to improve performance of passive radar, but the range and Doppler migration may occur for high-speed and accelerated targets, and for non-uniform sampled signal in the slow time such as China mobile multimedia broadcasting signal, the most used migration compensation algorithms such as Keystone transform and Radon-Fourier transform are inapplicable. This paper uses a long-time coherent integration algorithm based on two-step Doppler processing, which can be applied to both the uniform and non-uniform sampled signal, a modified algorithm based on this method is proposed, which can detect higher speed-acceleration targets, and this algorithm can improve computation efficiency. The specialty and difficulty of non-uniform sampled signal are analyzed first, then on the basis of Doppler processing of certain signal, migration reason and migration compensation principle are demonstrated. Finally, simulation and real data processing confirm the effectiveness of the proposed method.