Based on the rapid response advantages and test problems of the thin film resistor, the analysis and research on two aspects are focused: First, the thin film resistor is used as a current sensor which is applied in high-voltage DC transformer. The structure and performance of the thin film resistor are analyzed and simulated. Second, the dynamic characteristics of the thin film resistor are tested by indirect temperature measurement method. The problem of current rapid temperature measurement is solved. The dynamic temperature characteristic curve of the thin film resistor is analyzed by using multi-exponential spectral analysis method. The thermal characteristics of the fine structure for the thin film resistor are described by spectral characteristics. Moreover, more test information of the fine structure from comprehensive test results is separated to guide the improvement of the thin film resistor structure.