The slow imaging speed of traditional Optical Coherence Tomography (OCT) system limits the practical researches and applications of OCT , so a kind of fast OCT system without scanning frequency-domain was presented. The imaging resolution ratio, the depth of investigation and a variety of noise were analyzed, and a new method for eliminating background noise was brought forward. Based on the characters of the frequency-domain OCT and imaging spectrometers, the OCT system collected data rapidly with the line-focus mode and a new interferential optical path. Experimental results indicates that the two-dimensional tomographic image can be obtained without any scanning drive unit, the imaging speed for a glass slide which has 8mm width is two orders of magnitude quicker than the traditional point scanning mode and the background noise is eliminated successfully with the data processing algorithm.