We present a novel high-throughput imaging spectrometer based on over-scanning. The traditional slit-based spectrometer cannot gather enough radiation while the source is too weak. A much wider slit is used to replace the narrow one in traditional spectrometer. Too much wide slit will cause overlapping between different wavelength lights. In order to reconstruct super-resolution spectrum of source, over-scanning is employed which is realized by high precision electromechanical device. Experiments show that the reconstructed spectrum achieved a much higher resolution than original data meanwhile the throughput has improved significantly.