It is significant to measure visibility accurately in real time for guiding the traffic early warning and air quality assessment. The principles of forward scattering visibility meters are depicted,and the detection techniques and methods in the laboratory are introduced briefly. Based on the visibility environment simulation cabin developed by the Anhui Atmospheric Observation and Technical Support Center, multiple forward scattering visibility meters produced by three domestic manufacturers are tested. The consistency of various visibility values is examined,and the reasons for deviation are analyzed. In present, there is no standard verification scheme for visibility meters, so a method by using system constant calibration is proposed to reduce the measurement errors. The results show that visibility values are in good consistency with forward scattering visibility meters produced by the same manufacturer. The maximum of standard deviation is 1313 m when visibility is less than 15 km, and 4574 m in 15 to 10 km visibility condition. But there are obvious deviations for the meters produced by different manufacturers with the maximum of relative error up to -409% in 15 to 10 km visibility condition. After the calibration of the system constant,the accuracy of forward scattering visibility meters is improved obviously.