Abstract: A new operation model for joint optical multi-band detection systems is provided corresponding to the different characters of the detection probabilities of subsystems. It leads to a higher over-all detection probability. The joint optical detection system is able to operate under different models when detection probabilities of subsystems are low and when there is big difference among the probabilities. The joint optical detection detection system directly conducts data fusing under the former condition. And information from the subsystems is chosen before entering the fusion center under the latter condition. In this way, the false-alarm probability of a joint optical detection system reduces obviously comparing with direct data fusion.