In order to improve the utilization efficiency of brackish water in high altitude areas, maize, sunflower and potato in Qinghe County experimental area were taken as research objects to analyze the effects of magnetized brackish water treatment on the growth, development and yield of crops. Then, the growth model of sunflower under magnetized brackish water irrigation was established to analyze the relationship between growth characteristics and flower disc diameter. The results showed that compared with the conventional irrigation field experiment, the growth and development characteristics of the three crops in the study area were significantly enhanced, and the yield of each crop was increased by 28.90%, 18.27% and 8.19%, respectively. There was a strong correlation between the growth and development characteristics of the sunflower treated with magnetized brackish water. According to the multivariate linear regression model, the flower disc diameter was highly correlated with growth charateristics of sunflower, and the fitting coefficient R2 was 0.942. It is found that magnetized brackish water irrigation in high altitude areas can effectively enhance the growth characteristics of crops and increase their yield. The research results can provide a theoretical basis for the popularization of magnetized brackish water equipment in high altitude irrigation areas.