Abstract: A same-time-domain multi-frequency band hydraulic system, comprising a high-frequency data processing system, a control system, an executive system, a load, a static measuring system, and a dynamic measuring system, wherein the high-frequency data processing system processes the input command signals, data from the dynamic measuring system, and data from the static measuring system, and automatically generates, displays, and saves same-time-domain multi-frequency band test result data, wherein part of input signals are converted into input signals of the control system by the high-frequency data processing system and executed by the executive system, wherein the frequency response and measurement accuracy of the dynamic measuring system and the front-end data processing system meet the requirements of both the test and the hydraulic testing system.