DTF serial sun-photometers are used to measure aerosol optical thickness and precipitable water vapor in Hefei. Comparing with other type instruments by experiment measurement, it is obvious that the daily variation tendency is basically consistent. The errors of computed parameters between DTF sun-photometer and other devices are analyzed. The results indicate that the root-mean-square errors of measured aerosol optical thickness and precipitable water vapor are all less than 8%. Comparing precipitable water vapor measured by sun-photometer with microwave radiometer, the root-mean-square error is about 5%. Via comparison certification and error analysis, DTF sun-photometer which is used to measure aerosol optical thickness and precipitable water vapor has high reliability.