The simulations of the noise distribution of vacuum state, single photon state and squeezed state in phase space were presented by Wigner function, respectively and the technology of the quantum lidar based on the squeezed field was systematically analyzed, including quantum coherent lidar and quantum lidar with squeezed light injection. Compared to the classical lidar, a higher squeezing degree benefits improvement of the detection Signal-To-Noise Ratio (SNR) for quantum coherent lidar, and a squeezing degree of 8dB would afford a 6.25-fold improvement in SNR theoretically, while the quantum lidar with squeezed vacuum injection has higher spatial resolution, which depends on the squeezing level of the squeezed vacuum and the gain of the phase sensitive amplifier. The results show that the quantum lidar has obvious advantages in the fields of weak signal detection and high-resolution imaging as the improvements of the signal-to-noise by using squeezed light.