In situ heating experiments are a new hot spot in synchrotron radiation small angle X-ray scattering (SAXS) field. A simple synchrotron radiation SAXS in situ special device for sample heating is reported herein, recently designed by author, mainly containing thermostat, the sample cell, holder. The feature of the device is simple structure and easy operation. This article mainly describes the basic structure of the device, characteristics of the device and uses the device operate an in situ heating and drying experiment of lignite, then analyzes experimental results verifying the feasibility of the device.