As one of effective methods for antiradiation weapon against radar switching off, the passivelocation algorithm has been well studied. However, most passivelocation algorithm research has been undertaken based on the condition that antiradiation seekers work continuously. Accordingly, a passivelocation algorithm in view of discontinuous guidance for antiradiation UAV(unmanned aerial vehicle) is studied, and a method to solve the problem based on the Kalman filtering is proposed. Simulated results are presented to demonstrate the effectiveness of the method. Results show that this method can be used for unequal interval discontinuous guidance and it has certain location accuracy.