The wind field effect on the phase velocities of 3- to 10-meter Farley-Buneman two-stream waves in the equatorial E region ionosphere at altitudes in the range of 95 - 110 km is studied by numerical simulation. The behavior of this two-stream wave in the uniform wind field U_n in a plane perpendicular to the Earth’s magnetic field is simulated with a two-dimensional two-fluid code in which electron inertia is neglected while ion inertia is retained. It is confirmed that, the threshold condition for the appearance of two-stream waves is V^th_D ≈  (1 + ψ₀)C_s / cos θ + U_n ; and the phase velocity of the two-stream wave at the threshold condition is V_p ≈ C_s + U_n cos θ, where θ is the elevation angle of the wave propagation in a limited range and Ψ₀ = ν_inν_en / Ω_iΩ_e. The first formula in dicates that the wind field parallel (anti-parallel) to the electron drift velocity will raise (lower) the threshold drift velocity by the amount of the wind speed. This means that parallel wind is a stable factor, while anti-parallel wind is an unstable factor of two-stream waves. This may explain why high speed (larger than acoustic speed) two-stream waves were rarely observed, since larger threshold drift velocity demands larger polarization electric field. The result of the simulations at the saturation stage show that when V_D was only slightly larger than V_D ^th , the horizontal phase velocity of the two-stream wave would gradually down-shift to the thresh old phase ve loc ity C_s + U_n. The physical implications of which are discussed.