In order to simultaneously obtain the total atmospheric transmittance and precipitable water vapor at night under clear sky and cloudless view conditions, a research platform for stellar radiation measurement is built by combining telescope, multi-band filter, and near infrared enhanced CCD radiometer. First, the stellar radiation is collected by telescope. The radiation is filtered by sub-band filter, and the star image is collected by CCD. The gray value of the acquired image is further extracted, and the total atmospheric transmittance is calculated by Langley calibration method. At the same time, the precipitable water vapor is calculated by using the improved Langley method. The measurement results are compared with those of lidar and microwave radiometer to verify the reliability of the measurement method. The work in this paper enriches the means of simultaneous measurement of total atmospheric transmittance and precipitable water vapor at night, and has certain application value for space remote sensing and meteorological research.