The strong edge in an infrared image is an important factor restricting the infrared dim target detection probability and also an important source of target false alarm. By taking advantages of bilateral filters characteristics of the Euclidean distance of neighbor pixel and the similarity of pixel gray value, as well as the slowchanging interframe background, we defined the spatialtemporal bilateral filter and verified the inhibitory effect of this algorithm in the good complex backgrond. Results show that it can retain the target energy substantial and improve the local signaltoclutter ratio(SCR), the signaltonoise ratio gain(GSNR) is greater than 3.6 and the target energy suppress factor is less than 0.2.