Abstract: The analytical expression of oblique channel lightning electromagnetic field is obtained by decomposing the micro dipole and solving the Maxwell’s equations.The distribution laws of lightning electromagnetic fields with different azimuth and return-stroke speed is researched based on oblique channel model.The results show that tilt degree of oblique channel affects the distribution laws of electric field component variation with azimuth in near area， but the initial peak of electric field in intermediate area and far area as well as the magnetic field in any field area decrease with the increasing of azimuth.When lightning return stroke speed changes， the distribution laws of electromagnetic field in near area is unchanged， the initial peak of electromagnetic field in intermediate area and far area increases with the increasing of return stock speed.