Two cloud observation equipment, laser ceilometers and visible cloudmeters, are comparedIt is found that different factors have different effects on the observing performance of the devicesThe results provide theoretical basis for improving the observing performance of the cloud observation devicesThe results show that the devices affected by cloud physical properties and some weather phenomena such as fog, haze, and precipitation, so there will be false and missing records in the measurementsLaser ceilometers are affected by their own probe heights and vertical resolution, so have poor catch rates for high and thin clouds