In this article, the combination of a flat plate solar collector with a solar still is used for water desalination. The purpose of this study is to increase the output of the solar still by improving its performance by using a whole flat plate and investigating the effect of solar water on the amount of distilled water produced. Various effects, environment, water depth, environment, speed, and solar radiation have been studied to increase productivity. The results showed that coupling solar still with a solar collector increases the efficiency by 48%. Also, the amount of water depth in the distillation device affects the production of distilled water, and it is clear that by decreasing the depth from 3 cm to 2 cm, the amount of freshwater produced increases by 8.5%. The results obtained from the tests showed that the volume of distilled water output from the device, for an average depth of 2 cm to 4 cm, is 4.6 to 9.5 L/day using the collector and 2.4 to 1.3 L/day. It is without using it. The average radiation intensity and wind speed during the test with the collector were 1035 W/m2 and 3.7 m/s, respectively, and in the test without the collector, it was 980 W/m2 and 4.2 m/s.