The invention provides a device applied in gradient temperature control. The device is composed of a first temperature control module, a second temperature control module, a control module, a transmission device or a rotation device, a controlled target and a detection module. The method and device of the invention has the advantage of good expandability, different temperature control modules can be alternately used at different time points, the temperature control module in the off-working state adopts the idle time to realize the next target temperature value, sudden changes do not needed, and the service life can be prolonged; the temperature control module in the working state does not undergo the temperature rising/falling process, so the sample module temperature rising/falling rate can be improved, the overshoot phenomenon can be avoided, and the complex control algorithm does not needed. The temperature control is more flexible, the effective temperature control time of the controlled target can be shortened, the temperature change rate of the controlled target can be improved, and the application in gradient temperature control can be realized. Less temperature control modules are adopted, and different temperature control modules are used to control the temperature of the controlled target in different time periods through the idea of 'time division multiplex access' so as to realize a plurality of target gradient temperatures.