Small modular reactor has attracted increasing attention owing to its highly enhanced safety as well as improved economics. One type of the most important and widely-used parts in the advanced reactor is the complex helical tube heat-exchanger. In manufacturing of such kind of spatial three-dimensional bent tubes, springback induced shape deviation a challenging issue affecting the geometry dimension. In this research, using a superalloy tube as the case, an analytical method is developed to seek for an accurate, efficient evaluation of springback in spatial helical bending. To do this, the three-dimensional tube is firstly decomposed as two-dimensional geometrical configurations. Then, an analytical springback model is constructed with considering the real elasto-plastic properties and full geometry parameters. In addition, neutral layer shifting is introduced in the model to enhance the prediction accuracy. Using physical and numerical experiments, this method is validated and shows a high capability of springback evaluation.