Intelligent vibration reduction technology using magnetorheological fluid as the working medium has become a research hotspot in the field of vibration control. The preparation of high temperature resistant magnetorheological fluid can improve the vibration reduction performance of magnetorheological damper at high temperature. In this paper, the temperature rise characteristics of the magnetorheological damper during operation were tested, and the performance of the components of the magnetorheological fluid at high temperatures was studied. A high temperature resistant magnetorheological fluid was prepared based on high temperature resistant surfactant and hydrocarbon oil, and the rheological properties under different temperatures and magnetic fields were characterized. The Herschel-Bulkley model was used to analyze the nonlinearity in the fluid. The results show that the magnetorheological fluid has stable magnetic and rheological properties in the temperature range of 0 to 140 °C, and will not decrease significantly at high temperatures. It is expected to be used in most magnetorheological vibration reduction devices, especially high-power magnetorheological devices working at high temperatures.