To realize multi-channel laser cluster focal spot measurement and give its temporal and spatial resolution characteristics, a focal spot optical measurement platform based on imaging system, photodiode combined with oscilloscope, streak camera and scientific CCD is built. Before the experiment, the sensitivity and dynamic range of the scientific CCD and the performance parameters of the streak camera, such as gain coefficient, slit width and scanning time, were tested and calibrated off-line. The CCD is used to measure the spatial distribution of multi-channel laser cluster focal spot with time integration. By using photodiode combined with oscilloscope and streak camera, the time synchronization of multi-channel laser reaching the target is tested. The time-resolved characteristics of high-quality cluster focal spot are measured, and the fine spatio-temporal evolution image of spectral dispersion smooth beam focal spot is obtained. The test of focal spot shape and time synchronization of multi-beam channel laser cluster provide support for improving focal spot test technology and method of high-power laser device.