Abstract: We considered the self-consistent dust charge number in calculating ion wave instability growth rate, in order to survey the influence of electron depletion effect to dusty plasma ion wave instability growth rate. By comparing calculation results of several cases, we found that as the dust number density increases, electron depletion intensification could lead to the decrease of instability growth rate, and that the ion wave instability growth rate could be lower on the early stage of the released exhaust. The number density increase of either dust or neutral molecule can lead to the decrease of ion wave instability growth rate. This indicates that the assumption in present theory is not always correct.