Abstract: Time-interleaved ADC is a effective method to improve sample rate of radar receiver. But channel mismatch is introduced by this method, and channel mismatch degrades dynamic performance of system. Firstly, the hardware design of wideband radar receiver based on OpenVPX with a four-way TIADC structure was introduced. Then channel mismatch error and method of estimation were analyzed. Finally a online method of calibrating channel mismatch was proposed, which improved the efficiency of calibrating channel mismatch. The result of test showed that direct acquisition of 1GHz~4GHz IF signal at 9.6Gsps sample rate and 10 bit resolution could be realized by the design. Pulse compression result could fulfill the demand of wideband radar receiver, and the design had been applied in certain wideband radar.