A new CFAR detector(CMCAM) based on censored mean(CM) and cell average(CA) is proposed in this paper. Ln this detector the mean value of the local estimations of CM and CA is taken as the noise power estimation.Under Swerling Ⅱand homogeneous background assumption,the analytic expressions of Pd,Pfa and ADT are derived for the detector.The results show that the performance of CMCAM-CFAR detector is better than that of OS-CFAR detector in homogeneous background and multi-target situation.