In order to increase operating efficency of the ground-based electro-optic telescope for space debris observation，the evaluation model of detected ability for ground-based electro-optic telescope model was constructed. The model concludes geometry crossing of space debris, calculation for signal irradiation of space debris and background source, projecting for source signal to sensor plane, and calculation of detected signal to noise as basis of detectable judgement, etc. Observation test about geostationary earth orbit with 1m telescope was done for modelling verification. The conclusion shows that four background stars in Tycho-2catalogue crossing field of view in observation testwas observed, the number is same with simulation. the maximum difference magnitude for space debris of test compared to simulation was as much as 1.58, and it was mainly due to the feature of debris such as shape, it was with reason. The ground-based electro-optic telescope model based in signal-to-noise detected theory wsa reasonable,it can support suggestions for detected device construction, observed strategy design, etc.