In this paper, the impact of fin number on device performance and hot carrier induced device degradation was investigated for n-channel tri-gate multi-fin FinFET with different fin numbers. The threshold voltage (VTH) shift, transconductance, and subthreshold swing degradation were extracted to determine the degradation of device. It was found that the device with fewer fins shows better device performance, but suffer from more serious hot carrier induced device degradation. It is suggested that the existed coupling effect between the fins reduces the equivalent electric field in the multi-fins devices, thus shows better reliability than the single-fin device does after hot carrier stress.