As the parallel computing technologies are becoming mature, the research on parallelization of geospatial raster data processing algorithms has been a hot spot issue. Focusing on the complicated algorithms whose processing procedures consist of multiple computing steps, this research proposes a task scheduling method based on the theory of spatial computational domain with which the task scheduling solution is not static, but adjusts itself as the algorithmic procedure proceeding. Experiments have verified the effectiveness of our method. Because the method keeps adjusting the task scheduling solution at every computing step, the load-balancing effect is better, and thus the parallel running time is shorter compared with the conventional task scheduling method.