The invention discloses a multimode MRI (
Magnetic Resonance Imaging) 
longitudinal data-based 
brain tumor space-time coordinative segmentation method. The method comprises pre-operation segmentation 
processing and post-operation segmentation 
processing. The post-operation segmentation 
processing comprises the processes of (1) obtaining 
brain tumor post-operation MRI data; (2) mapping the 
longitudinal data to a 
time domain and a space domain for performing segmentation processing, wherein the 
time domain segmentation comprises the processes of obtaining a pre-operation segmentation result and longitudinal to-be-segmented data, performing pre-operation and post-operation 
image registration, and building a post-operation 
tumor growth model; the space domain segmentation comprises the processes of constructing symmetric templates of different tissues of normal brain, extracting Haar structure features, obtaining an initial probability result by combining a structure 
random forest method with an 
AdaBoost framework, performing 
label growth by utilizing a similar region growth 
algorithm, and obtaining a space domain segmentation result; and (3) building a four-dimensional 
graph model in combination with 
time domain and space domain segmentation results, and optimizing obtained parameters to form an 
automatic segmentation result. Therefore, the accuracy of 
brain tumor region segmentation is improved.