The advantages of scannerless lidar and the operating principle of streak tube imaging lidar are introduced; the relationship between range resolution and spatial resolution is expounded. Based on analysis of the key factors that influence the spatial resolution of streak tube imaging lidar, the equation to calculate the overall spatial resolution is founded, and corresponding mathematical analyses are also made to predict the performance, finally, by means of resolution panel, we set up experiment to validate the spatial distinguishing ability of the system and get the raw resolution image and process the image by noise filtering. Through calculation of the contrast transfer function, we get the practical spatial resolution data and make performance analysis by comparing the practical data with theoretical data.