With the aim of improving the performance of IF sampling system, reduce the board-level noise, increase the flexibility of the sampling system, this paper designs and implements a high performance IF sampling system. The system implements a configurable sampling clock with AD9518-4 device. AD9518-4 can provide multichannel outputs with different frequency. The system uses AD8352 operational amplifier which can transform the single-ended signal into the differential signal, amplify and filter the signal as the driver of ADC front-end. The system can obtain 14bit low voltage differential signal with AD9445 analog digital converter. Experimental results show that, the signal to noise rate can reach 77.4dBFS when the input signal frequency is 40MHz and the system can achieve a configurable sampling clock. The RSN, SFDR and ENOB of the sampling system are all obviously improved compared with the traditional scheme.