The present invention provides a method, a device, and a system for inter-frequency cell measurement. The method includes: performing, by a terminal, when receiving a measurement command of a network side device, inter-frequency cell measurement, in different cases, based on the time specified in different measurement time parameters or based on measurement time parameters corresponding to the information about an inter-frequency band. As different measurement time parameters specify different time actually used for measurement, not only an inter-frequency cell that meets a measurement event can be measured, but also the time for measurement by the terminal can be reduced, thereby reducing the power consumption of the terminal and enhancing the performance of the terminal.