How to continuously and effectively detect the target position in a complex background has always been a major challenge for researchers.Based on the research of infrared point moving target characteristics,this paper proposes an improved morphological target enhancement algorithm based on the target′s non-texture and shape-free characteristics,and uses the target continuous spatiotemporal invariance to detect the target.First,a multi-scale image pyramid is created,and an improved morphological algorithm is used on each layer to quickly and coarsely locate small targets.Then according to the positional correlation of the target in time and space,an accurate detection method based on the analysis of the target motion characteristics is proposed.Accurate and stable test results are obtained .Finally,the experimental results show that compared with the classical morphological detection algorithm or single frame detection algorithm,this technique can detect weakness targets more effectively and has higher robustness.