Laser spot floating impacts the use of laser atmosphere transmission greatly.This paper designed a system based on virtual instrument to measure the laser atmosphere transmission spot floating.The core of the system is LabVIEW software,a product of NI,through the hardware interface of which and CCD we can capture the laser spot images,by the software interface of which we can use Matlab,which is powerful in data processing,to process the signals and analyze the spot floating.This system provided a new way of laser atmosphere transmission characteristic measurement.