Aim at the problem of detecting for distant small target with very low SNR,a method of two color IR small target fusion detection using D-S evidence theory is proposed. The algorithm firstly detects targets from each sensor using statistics detection method and fuses the results using "OR" logic to reduce the probability of being missed.Then extracts the multiple image features of these target candidate areas in fusion detection result from the two sensor images as the evidence to eliminate false detection.Finally, distinguishes the false target from real target using the D-S evidence theory based on multiple features, and sends the recognition result to the target detection output of the whole system.