The coil electromagnetic radiator is widely used in underwater weapon system and underwater active electromagnetic detection, and it’s an essential part of electromagnetic fuze, active electromagnetic detection and other systems. The main parameters to measure the electromagnetic radiator are coil turns, inductance and radiation intensity. In this paper, the relationship between coil turns, inductance and radiation intensity of electromagnetic radiator is analyzed. Through theoretical analysis and experimental test, we can draw the following useful conclusion: Although increasing the number of coil turns can improve the radiation magnetic moment of unit exciting current, too many turns of coil is not good for engineering implementation. Therefore, in practical application, the relationship between coil turns, size, inductance and magnetic moment of the radiator should be considered comprehensively.