In order to improve the accuracy of warship combat system alignment in dynamic state, the author has taken shipborne 3D radar as an example to study the effects on alignment in dynamic state of warship combat system caused by its attitude. A coordinate system aligned combat system was established in this paper, the mainly coordinate conversion were derived, sensor measurement errors caused by warship's attitude were calculated and simulated by computer. Simulation results show that: the warship's heading angle causes the azimuth angle error of sensor measurements, the warship's pitch angle, roll angle cause the angle azimuth and elevation angle error of sensor measurements, and there is almost no influence on sensor distance measurement caused by warship's attitude. Error correction is need in the subsequent data processing of dynamic alignment to meet the requirements of warship combat system alignment in dynamic state.