A NdYAG laser emits two 532-nm laser beams to pump two pulsed dye lasers, respectively. Then one dye laser will emit a 589-nm laser beam for Na layer detection, while the 770-nm laser beam for K layer detection is obtained from the other dye laser. The scattering echoes of these two laser beams are collected with the same telescope, and transmitted by two fibers set in the telescope′s focal plane, respectively. Therefore, we have realized the simultaneous observation of Na layer and K layer by using only one lidar system and have gotten a new and economic detection tool for upper atmospheric Na layer and K layer observation.