The cognitive bias is an objective existence of cognitive electronic warfare. Based on the method of dynamic gaming, this paper investigates the approach to modeling radar countermeasure with the cognitive bias caused by the incomplete information and the measuring error in the cognitive radar countermeasure. It adopts the anti-jamming improvement factors of radar and the jamming payoff factors of jammer to calculate the utilities of both adversarial parties. Thereafter, the dynamic radar countermeasure model is setup with the perfect Bayesian equilibrium. The influence of cognitive bias on gaming result is further analyzed. The results of simulation test validate the effectiveness of the proposed method.