In this work， the auto-ignition behaviors of FOX-7/NC/NG powder were investigated by using rapid compression machine （RCM） under a high temperature environment. High speed images and pressure evolutions were used to record the responses of FOX-7/NC/NG samples under high temperature and pressure conditions. Results show that the samples were not able to ignite at 3.0 MPa and 598.1 K， with the heating rate of about 1.2×10⁴ K·s^-1. With the temperature increasing to 913.1 K （the heating rate is about 2.5×10⁴ K·s^-1）， the auto-ignition was observed. In addition， the validated tests of FOX-7/NC/NG samples were conducted. Results show that the experiment has a good repeatability. The uncertainties of ignition delay times （IDT_I） and burning duration are less than 20% and 5%， respectively. Lastly， the auto-ignition behaviors of FOX-7/NC/NG samples were studied at different thermal loading rates. It was found that the higher thermal loading rate， the faster ignition and the shorter burning duration.