A multi-frame interferometer and shadowgraph system based on angular-spectrum-division all-optical frame imaging technique has been developed. The system is capable of shooting 2~4 high definition shadowgraphs or interferograms in one shot with frame interval of 3~12 ns. By the 4f differential interferometer structure, the system is applicable for diagnostics of electron density of Z-pinch plasma with high temporal and spatial resolution of large density gradient. In the cylindrical single-shell tungsten wire array Z-pinch experiments conducted on Primary Test Stand, a sequentially timed shadowgraphs of implosion plasma give implosion velocity, compression ratio, magneto Rayleigh Taylor (MRT) instability evolution, etc. In the planar tungsten wire array experiments conducted on XP-1, the interferograms and calculated electron densities give plasma distribution and evolution in the early stage of wire array ablation.