Using a single-mode laser cubic model driven by additive colored noise and multiplicative colored noise，through theory of Novikov，Fox approximation and the approximation of Stratonovich，an expression of intensity correlation function C was reached at. The effects of the correlation time τ，the net gain a0 and the cross-correlation intensity λ on the intensity correlation function C was investigated. The result of numerical simulation shows that the intensity correlation function C increases with the correlation time τ for the net gain above the threshold （a0>0），but decreases as correlation time increases for the net gain below the threshold （a0C decreases as cross-correlation λ intensity increases no matter the net gain is above or below the threshold. The curve of C versus a0 has a single peak.