Abstract Much attention has been paid to the photoresponse of vanaduim oxide (VOx) and amorphous silicon based microbolometer for long-wavelength infrared detection under un-cooled operation condition in recent decades. However, the outstanding physical and chemical properties of graphene and reduced graphene oxide (rGO) stimulate their potential for use in light-sensitive applications. Much less attention has been paid to investigate the performance on long-wavelength infrared detection of microbolometer using reduced graphene oxide/SiNx/vanadium oxide composite films deposited on under room temperature operation. In the research, we have proposed the novel microbolometer based on VOx/SiNx/rGO composite films replace the as-deposited VOx based microbolometer. It is noted that such extraordinary properties (high responsivity: 18,130 V/W and low NETD: 43.32 mK) of the VOx/SiNx/rGO composite presented here encourage us to contemplate on this protocol for next generation optoelectronic device engineering for infrared detection.