In order to calculate the radiation field of a annular torpedo electromagnetic fuze radiator, the annular radiator is equivalent to an orthogonal magnetic dipole, and the expression of the magnetic moment components is given. Through the decomposition and superposition of the radiation field produced by each magnetic moment component, the mathematical model of the annular radiator radiation field is derived. The simulation results show that the radiation field of the annular radiator has good symmetry and uniformity, which can meet the detection requirements of anti-ship and anti-submarine electromagnetic fuze for torpedo passing through the target.