In this study, the ability of Spirulina platensis microalgae in dairy wastewater treatment and nutrient removal associated with biomass production was evaluated. Therefore, two concentrations of Spirulina platensis (0/05 and 0/1 g/L) were cultured in three dilutions (25, 50, 75%) of dairy wastewater and the efficiency of nutrient removal and biomass production was evaluated with six treatments in three replications. Nutrient and biomass values ​​were measured on every other day. The results showed that both factors of different concentrations of algae and different dilutions of wastewater had an important role in nutrient absorption and biomass production. The highest percentages of nitrate, phosphate, ammonia removal (99/85, 82/60, 99/83%) and maximum amount of biomass (1/690±0/01 g/l) in 25% dilution and concentration of 0/1 g/l microalgae was obtained. In this research, by decreasing percentage of dilution of dairy industry wastewater and increasing amount of nutrients available in microalgae and also by increasing the initial concentration of injectable microalgae in the wastewater, more nutrients were removed, and the nitrate and ammonia levels were almost 100% eliminated and the amount of biomass increased. As a result, according to the results, Spirulina platensis microalgae has a high performance in removing nutrients (nitrate, phosphate, ammonia) from dairy industry wastewater and can be considered for dairy industry wastewater treatment.