There are many kinds of microalgae, which can be widely used in aquaculture, food manufacturing, biomass energy or water treatment, and carbon sequestration. In recent years, due to the increasingly intensified climate change, the global temperature has shown extreme development, which has severely affected the growth of algae and reduced the effectiveness of the application. To face the challenge of extreme weather, this project attempts to develop algae that can be used by all walks of life, select microalgae with extreme cold and heat resistance potential from natural water bodies, and explore their ability to adapt to temperature adversity to expand their potential Use the application characteristics of microalgae to lay the foundation for subsequent research and application. In this experiment, the microalgae were collected from the field, cultured in a constant temperature growth box, and then separated and purified. A total of 5 strains of microalgae were screened out, namely, Coscinodiscus U1 and S35, Melosidopsis ME, Nitzschia NI, and Diatom R1, the current test results show that U1 extreme temperature adaptation range is 5-36℃; S35 extreme temperature adaptation range is 5-39℃; ME extreme temperature adaptation range is 5-36℃; NI extreme temperature adaptation range is 5-30 ℃; the extreme temperature adaptation range of R1 is 5-39℃. Although these algae strains grow slowly or even stagnate under low-temperature conditions, they do not die. Once the room temperature is restored, they can grow normally; under high-temperature cultivation, algae other than NI In the early stage of the plant, there is a trend of rapid growth, but due to the short life history of diatoms, it is prone to rapid proliferation and rapid decline, so the concentration of the high-temperature culture begins to decrease in the middle of the culture. In terms of algae composition: R1 has the highest moisture content (19.12±0.31%); ash content is also the highest R1 (23.83±0.75%); crude protein content is the highest with ME (39.70±0.39%); lipid content is the highest S35 is the highest (23.62±0.08%). The test results show that although both U1 and S35 are Coscinodiscus, their growth characteristics, temperature adaptability, and nutritional composition are quite different. Therefore, by artificially regulating the culture conditions and directional selection of them, algae strains with ideal characteristics or application potential can be obtained.