In order to achieve measurement of atmospheric temperature, water vapor (relative humidity) and aerosol simultaneously, a Raman lidar system has been developed, and a high-performance spectroscopic box composed of dichroic mirrors and narrow-band interference filters is used to separate the different-wavelength lidar return signal and to extract the interested return signal with high efficiency. The method is proposed for profiling the atmospheric water vapor density, temperature and aerosol extinction coefficient, and thus the profile of relative humidity is obtained. Preliminary experiments are carried out for simultaneous atmospheric parameter detection in Xi′an under clear and cloudy conditions, the vertical profiles of water vapor density, temperature, relative humidity and aerosol extinction coefficient are analyzed, and the variation in water vapor in the clouds and the inversion layer is obtained. The observed results show that under the conditions of integration time of 15 min and laser energy of 150 mJ, the effective simultaneous detection range for temperature and relative humidity achieves up to 16 km under clear condition, the temperature inversion layer is obtained in the lower atmospheric layer and at the top of the cloud layer, and synchronization increasing trend is found between water vapor density and relative humidity within the high cloud layer and water vapor layer. The obtained results are better consistent with radiosonde data in terms of the water vapor density, temperature and relative humidity profiles, which verifies the reliability of the Raman lidar to achieve real-time multi-parameter measurement up to troposphere height, and long-term observation and studies can be conducted to provide reliable data for research of climate change and haze process.