In order to improve the long-term frequency stability and phase noise of optoelectronic oscillator (OEO) output signal,a kind of single-loop optoelectronic oscillator based on t he theory of Rb atomic frequency standard and electric injection locking is presented in this paper.The injectio n-locked scheme injects the standard sinusoidal signal which is presented by Rb atomic frequency standard into the si ngle-loop OEO,the frequency of the free oscillation signal is pulled by the injected signal,and there is only t he principal mode in the oscillator.It can be seen in the experiment that the greater the power of the standard injected s ignal is,the better the locked bandwidth is,and the worse the phase noise of locked signal is.With decreasing o f the locked signal power,the locked bandwidth declines,and the phase noise of locked signal is close to that of the standard injected signal.The experimental results show that under the condition of the fiber length of 10km, the frequency of the output signal is 10GHz,the side mode suppression rate is more than 60dB,the measured phase nois e of －76dBc/Hz at 100Hz and －108dBc/Hz at 10kHz is obtained,and the long- term frequency stability and accuracy of the output signal have been improved.The results of the experiment are consistent with the theoret ical analysis.