An all time multi-wavelength lidar system used for the detection of troposphere atmospheric aerosols is developed. It utilizes the beams of 1064, 532 and 355 nm emitted by a Nd:YAG laser at the frequency of 10 Hz. This multi-wavelength lidar realizes the precise separation and extraction of Mie scattering signal at ultraviolet, visible and infrared wavelengths. The sky background noise is strongly restrained by using aperture and interference filters, and the all time detection is achieved. The signal to noise ratios (SNR) of actual detection results are compared with simulation results at three wavelengths. It is found that the SNR at 532 nm is the lowest in the daytime detection; however, the SNR at 355 nm is the lowest in the nighttime detection. This result is consistent with the theoretical calculation. The detection height can reach 8~10 km in the daytime and 10~12 km in the nighttime, providing the actual detection SNR is 1. The results of actual detection in Xi′an in fine, cloudy and haze days show that the multiwavelength lidar can fully satisfy the need for detection of troposphere atmospheric aerosol particles at all time and under various weather conditions.