Disclosed is a solar wastewater treatment device including a shell unit, an atomizing unit, a pressurization unit, a pressure valve, a discharge unit and a heat collecting unit. The shell unit includes an inner wall, an outer wall, a plurality of thermal conductive particles and a cover body. The heat collecting unit includes a plurality of heat collecting rods, a plurality of light concentrating plates and a plurality of thermal conductive particles. Each heat collecting rod has a tube body and a thermal insulation layer, wherein each tube body has a heat conductive end distachably connected to the shell unit and a plurality of heat collecting regions. The light concentrating plates respectively correspond to the heat collecting regions to be installed at the tube body. The thermal conductive particles are suspended inside the tube body. By using the heat collecting unit to collect the solar energy and transfer heat to the shell unit, the wastewater can be heated to be cleaner vapor and then is discharged from the discharge unit. Thereby, this device has the effects of cost saving and environment protection.