With the development of electronic technology, constant beamwidth beam forming techniques are widely applied in electronic reconnaissance system in complex electromagnetism environments. In this article, the principles of wideband constant beamwidth optical multi-beam forming are introduced, the method is introduced for obtaining the sub-frequency band weighting matrix for shaping frequency invariant beam pattern by means of window functions, and the system design scheme of wideband constant beamwidth optical multi-beam forming is proposed. Simulation results demonstrate that the proposed method can form the pattern with constant beamwidth and better direction.