Aiming at laser weapon damage to anti-ship missile, laser damage to IR guidance anti-ship missile detectors was researched. First, model on laser weapon damage to IR guidance anti-ship missile detectors was set up. Then 1.06μm and 10.6μm laser atmospheric transmittance on the sea was calculated. Finally, 10.6μm laser was given as an example, the necessary laser energy which can damage effectively the IR guidance anti-ship missile detectors was calculated. Some valuable data and conclusions were gained. It is concluded that laser weapon damage to IR guidance anti-ship missile is feasible at present.